Module 4 v
1. A junction diodea) has one p-n junctionb)is similar to a
vacuum diode but cannot rectifyc) can handle only small
currents
2. A germanium diode is used fora) voltage
stabilisationb)rectificationc) signal detection
3. A germanium diodea) has a lower forward bias voltage than a
silicon diodeb)has a higher forward bias voltage than a silicon
diodec) has the same forward bias voltage as a silicon diode
4. a VLSIC hasa) less than 1000 gatesb)more than 1000 gatesc)
more than 10,000 gates
5. A momentary input at the reset input of a flip flop willa)
reset the true output to 0b)reset the true output to 1c) clock in
new data from the data inputs
6. Which type of flip flop has only 1 data inputa) RSb)JKc)
D
7. A low pass filter hasa) a capacitor in series and an inductor
in parallelb)a capacitor in parallel and an inductor in seriesc)
both capacitor and inductor in parallel
8. When you use an op amp as a buffer it hasa) high input
impedance and low output impedanceb)low input impedance and high
output impedancec) the same input an output impedance
9. What switches off a thyristor?a) Remove the gate
voltageb)Remove supply voltagec) Reverse bias gate
10. When an SCR is switched on it hasa) high resistanceb)low
resistancec) no change in resistance
1. What is required for the switching of a monostable
multivibratora) one trigger pulse to switch on and another to
switch offb)one trigger pulse to both switch on and offc) one
trigger pulse to switch on and two trigger pulses to switchoff
2. A transistor at saturation hasa) high resistanceb)low
resistancec) zero resistance
3. A capacitor resistor coupled multistage amp letsa) AC and DC
pass to the next stageb)AC pass onlyc) DC pass only
4. An oscillator operating at its natural frequency has feedback
whichisa) inphaseb)90 degrees out of phasec) 180 degrees out of
phase
5. What type of diode when forward biased holes and electrons
recombineproducing photons?a) gunnb)LEDc) photodiode
6. What type of pulse is required to switch on a SCRa)
positiveb)negativec) positive and negative
7. Which mathematical operation is performed by a modulator
amplifier?a) Additionb)Subtractionc) Multiplication
8. What is meant by a bistable circuit?a) The circuit has 2
stable states and will stay in which one it is putb)The circuit has
2 stable states and will stay in both at the sametimec) The circuit
has 1 stable state and it can be negative or positive
9. A zener diode is designed to operatea) above its breakdown
voltageb)below its breakdown voltagec) either above or below its
breakdown voltage
10. A JFET isa) voltage sensitiveb)current sensitivec) either of
the above depending on resistance in the circuit
1. A triac is a type ofa) thyristorb)thermistorc) transistor
2. A piece of pure Germaniuma) has a deficit of electronsb)is
electrically stablec) has an excess of electrons
3. If a junction diode is reverse biased too far, the output
currentwoulda) cease to flowb)increasec) reverse direction
4. An RC connected amp hasa) no AC acrossb)no DC acrossc) even
amounts of d.c and a.c across
5. When a PN junction is forward biased, it conducts viaa)
majority carrierb)minority carrierc) intrinsic carrier
6. Thermal runaway in a transistor refers toa) high current flow
when temperature increasesb)low current flow when temperature
increasesc) high current flow when temperature decreases
7. When is maximum voltage induced into the rotor of a control
synchrotransformer?a) 90 degrees (null position)b)0 degreesc) When
spinning fast
8. Resistors and capacitors are used to couple stages of
amplifiers sothata) only d.c can be appliedb)equal amounts of a.c
and d.c can be appliedc) only a.c can be applied
9. An astable multivibrator is aa) free running vibratorb)one
which requires an input to switch on and offc) one which requires
no input whatsoever
10. Op amps use what power supply?a) 26v a.cb)5v - 15v d.cc) 26v
d.c
1. To check the output of a synchro stator it would be
preferable to usea) an Avometerb)a Valve Voltmeterc) a Cambridge
Bridge
2. Synchro capacitors are connected into synchro systems toa)
minimize the torque synchro stator current at nullb)increase the
accuracy of the control synchroc) act as spark suppression due to
wear of the slip rings
3. The purpose of the fly wheel incorporated in a synchroa) is
to increase the driving forceb)to prevent oscillationsc) to prevent
insect ingress
4. In a slab desynn transmitter thea) pick-offs form part of the
circuit resistanceb)pick-offs rotate on the slab resisterc)
pick-offs are connected to a spark suppressor
5. If, in a servo system, the amplitude from the feedback system
isbelow normal, the servo willa) oscillateb)be sluggish in
operationc) be overdamped
6. A desynn instrument has a positive irregular increasing
error, youwould adjusta) lever lengthb)lever anglec) lever angle
and lever length
7. Torque synchro receiver bearing friction will causea)
huntingb)misalignmentc) improved accuracy
8. A control synchro system pointer isa) actuated by a permanent
magnetb)displaced by the torque of the statorc) motor driven
9. A D.C. signal converted to a phase sensitive A.C. isa)
demodulationb)phase conversionc) modulation
10. If velocity feedback in a servo system is above optimum,
this willcausea) sluggish operationb)huntingc) has no effect
1. A device which has a high input impedance, low output
impedance andhigh voltage gain is aa) Class A ampb)Class B ampc)
Op-Amp
2. In an integrated circuit, the components are mounted bya)
wires connecting them using conformal coatingb)a three dimensional
process with no connections between them requiredc) metal oxide
film etched onto surface
3. For a NPN transistor to conduct the collector circuit has to
bea) more positive than the emitterb)more positive than the basec)
less positive than the emitter
4. The amount of rate feedback from a tachogenerator isa)
proportional to speedb)inversely proportional to speedc) constant
for all servo speeds
5. When forward biased, current flow is mainly due to thea)
majority carriersb)minority carriersc) germanium bias junction
6. When forward biased thea) positive lead is connected to the N
type and negative to the P typeb)positive lead is connected to the
P type and negative to the N typec) positive lead is connected to
both N and P type
7. In a PNP transistor, which way does conventional current
flow?a) Base to emitterb)Collector to emitterc) Emitter to
Collector
8.In the Zener Diode suppressor shown, point X in respect to
point Y shouldbe a) more negativeb)more Positivec) either positive
or negative
9. In an integrated circuit, the components are inserteda)
manuallyb)automaticallyc) by doping in successive layers
10. The typical voltage drop across an L.E.D isa) 2Vb)4Vc)
6V
1. In an electronic circuit with an operational amplifier
connected inthe push-pull configuration, the circuita) decreases
impedanceb)utilizes both sides of the input signalc) blocks half of
the input signal
2. Pin 3 on an op-amp has a + symbol. This designatesa) positive
offset nullb)positive input DC pinc) non-inverting input
3. An advantage of a FET when compared to a bi-polar transistor
isa) the input resistance is lowerb)the switching time is quickerc)
the input resistance is higher
4. The semiconductor substrate used in 'chips' is most
commonlya) germaniumb)siliconc) phiidide
7. What control system is used on an input that gives a
controlledpredetermined output?a) Open Loopb)Closed Loopc) Control
Servo
__________________Homer not function well beer without !
Module 4 vi
8. Increasing velocity feedback from optimum will givea)
sluggish performanceb)faster performancec) no change on the
output
9. A rate control servo system with a steady input voltage will
givea) constant speedb)increasing speedc) decreasing speed
10. Where are decoupling capacitors used in digital circuits?a)
Between pins 1 & 8b)Close to the +ve pinc) Close to the ve
pin
1. What are the majority carriers for a forward biased PN
junctiondevice?a) Electronsb)Holesc) Electrons and holes
2. The resistance measured using an AVO between the Collector
andEmitter of a transistor isa) same both waysb)smaller Collector
to Emitterc) higher Collector to Emitter
3. Germanium in its pure state isa) neutralb)positively
chargedc) negatively charged
4. Common Collector has the following characteristicsa) Medium
Voltage Gain, High Current Gain, Non-Inverted Outputb)Low Voltage
Gain, High Current Gain, Inverted Outputc) Medium Voltage Gain, Low
Current Gain, Inverted Output
5. Two push-pull transistors have what commoned?a)
Basesb)Collectorsc) Emitters
6. In a Common Emitter Amplifier RE is used fora)
biasingb)stabilisationc) load control
7. If the reverse bias voltage across a diode is too higha) load
current increases rapidlyb)load current reversesc) load current
reduces to zero
8. The rotor coil of a synchrotela) is stationaryb)rotatesc)
rotates only when a current flows in it
9. An increase in amplitude of a rate feedback signal will
causea) sluggish servo operationb)reduced huntingc) instable
operation
10. An increase in negative feedbacka) increases system
sensitivityb)decreases system sensitivityc) will make the driven
device continuously rotate
1. An integrated circuit is manufactured bya) computer hardware,
which use individual circuits on ribbonb)doping impurities into
layers of intrinsic materialc) etching copper tracks onto an
insulating board
2. A de-coupling capacitor in a PCB is used toa) minimise
transient currentsb)pass a.c onlyc) pass d.c only
3. A monostable vibratora) is switched on by a trigger pulse
then within a pre-set time willeventually return to its original
stateb)uses a trigger pulse to turn on and the same pulse to turn
offc) uses one pulse to turn on and another to turn off
4. Position feedback is used toa) ensure control surface moves
to the demanded position by thecontrolsb)to prevent control surface
oscillations while the surface is beingmovedc) indicate to the
pilot the position of the load
5. The output from a control transformer isa) torqueb)AC
voltagec) DC voltage
6. The stator output voltages from a synchro resolver area)
DCb)AC single phasec) 3 phase
7. The purpose of synchro capacitors in a differential
synchrotransmission systema) to reduce stator currentb)reduce rotor
currentc) reduce stator circuit impedance
8. A typical use for resolver synchros isa) in compass
comparitor unitsb)engine power instrumentationc) fly by wire
system
9. The purpose of a flywheel in a synchro receiver indicator is
toa) prevent spinning or oscillationb)encourage spinningc) increase
driving torque
10. A linear variometer isa) a special synchro giving ac output
proportional to shaft angleb)a special auto transformer for synchro
system power suppliesc) an alternative term for a desynn system
1. In a synchrotel the rotating winding isa) the statorb)rotorc)
neither
2. The receiver rotor in a torque synchro system oscillates over
an arcof approx 75 degrees. The probable cause isa) short circuit
between two stator linesb)two stator lines reversedc) one stator
line open circuit
3. Synchro capacitors are fitteda) to provide critical
dampingb)to make additional damping features unnecessaryc) to
improve sensitivity and accuracy
4. The output of a control transformer is madea) phase and
amplitude sensitive by direction and magnitude of thetransmitter
rotor movement respectivelyb)phase and amplitude sensitive by
magnitude and direction of thetransmitter rotor movement
respectivelyc) phase sensitive by transmitter rotor excitation and
amplitudesensitive by direction of transmitter rotor movement
5. A transistor is used ina) current amplifierb)voltage
amplifierc) both
6. An LED which emits green light usesa) gallium ****nide
phosphideb)gallium phosphidec) gallium ****nide
7. An LED which emits red light usesa) gallium ****nide
phosphideb)gallium phosphidec) gallium ****nide
8. A photodiode is operated undera) reverse bias
conditionsb)forward bias conditionsc) reverse or forward bias
conditions
9. To increase capacitance of a varactor diodea) reverse bias
voltage is increasedb)forward bias voltage is decreasedc) reverse
bias voltage is decreased
10. Which diode has a lower forward bias voltage?a)
siliconb)germaniumc) both the same
1. A Zener diode is used fora) rectificationb)voltage
stabilisationc) voltage regulation
4. A thyristor SCR is aa) unidirectional deviceb)bi-directional
devicec) multidirectional device
5. A bi-directional TRIAC has two SCRs connected ina) series
parallelb)parallel seriesc) inverse parallel
6. A thyristor can be forward biased bya) positive
pulseb)negative pulsec) positive or negative pulse
7. 'N' type materials are doped witha) acceptorsb)donorsc)
acceptors and donors
8. A junction diode if reverse biased too far, the output willa)
increaseb)stopc) reverse
9.The input of this circuit will bea)
integratedb)differentiatedc) logarithmic
10. The most suitable class of amplifier for a radio transmitter
isa) Ab)Bc) C
2. What is the base material of a PCB?a) Insulatorb)Conductorc)
Semiconductor
3. What does the output voltage of an op-amp depend upon?a) The
resistors in the circuitb)The op amp bandwidthc) The gain of the
op-amp
__________________Homer not function well beer without !
Module 4 iv
1. The cogging effect in synchros is rectified bya) using carbon
brushesb)using an elliptical cogc) skewing the rotor
2. A transistor is said to be in the quiescent state whena) no
signal is applied to the inputb)it is unbiasedc) no currents are
flowing
3. In an unbiased p-n junction, current flow isa) due to the
diffusion of minority carriers onlyb)zero, because no charges are
crossing the junctionc) zero, because equal but opposite currents
are crossing thejunction
4. Reversal of the power supply to either the transmitter or
thereceiver of a torque synchro system woulda) cause a 180o
displacement between the transmitter and the receiverb)have no
effect on the indication, but would cause a heavy current toflowc)
make the receiver rotor rotate in the opposite direction
5. Torque synchro systems are normally used when thea)
mechanical load is lowb)mechanical load is highc) system accuracy
is of extreme importance
6. A common base transistor circuit is so called becausea) the
base region is located between the emitter and collector
regionb)the base is n-type materialc) the base is common to the
emitter and collector circuits
7. What device transfers one energy type to another?a)
Transmitterb)Transducerc) Transponder
8. Which way does conventional current flow in a PNP junction?a)
Collector to emitterb)Emitter to basec) Collector to base
9. Electrical power is supplied to a synchro rotora)
directlyb)through slip ringsc) through a commutator
10. The purpose of a flywheel incorporated in a synchro is toa)
increase the driving forceb)prevent oscillationsc) prevent insect
ingress
1. In an operational amplifier, the two input waves are the
sameamplitude, same frequency, but exactly anti-phase. What would
the outputbe?a) Doubleb)Zeroc) Half
2. A thyristor has which of the following?a) High resistance
when switched onb)High resistance when switched offc) A positive
temperature coefficient
3. On an integrated circuit the hole in the top left corner is
pin 1.The pins are counteda) clockwiseb)anticlockwisec) from left
to right
4. With reference to the circuit shown below, how is the
transistorconfigured?a) Common emitterb)Common collectorc) Common
base
5. In the circuit diagram above, R1 and R2 are used toa) set the
transistor gainb)set the DC bias levelc) increase the base
voltage
6. In a synchro system, if two stator lines are crossed the
receiverwilla) not be affectedb)be 180o outc) reverse direction
7. In the following Boolean algebra statement, which gate is
described?F = A + B + Ca) Orb)Notc) And
8. In an E and I signal generator at datum, the voltage on the
secondarywindingsa) are equal and oppositeb)is maximumc) is
zero
9. In a synchro resolver, the stator coils are at what angle in
relationto one another?a) 45 degreesb)80 degrees c) 90 degrees
10. In a synchrotel, thea) rotor coil is fixed and the stator
coil movesb)rotor coil and stator coil is fixedc) stator coil is
fixed and the rotor coil moves
1. On a PCB, a decoupling capacitor is used to get rid of
transientcurrents between which points?a) The electronic circuit
and the aircraft groundb)Interspaced along the circuitc) The
negative rail and the rest of the circuit
3. In an LED, what is used to make the colour?a) The doping
materialb)The electronsc) The plastic lens cover
4. An atom with 5 electrons in its outer shell is part ofa) an N
type materialb)a P type materialc) a C type material
5. In a FET, the junction connections are calleda) drain, source
and gateb)base, collector and emitterc) drain, collector and
junctions
6. In the Boolean algebra statement below, the gate described
isF = A.B.Ca) Nandb)Norc) And
7. With a small amplitude voltage, what type of diode would you
use toproduce the output waveform?a) Shottkyb)Gunnc) Zener
8. An increase in negative feedback to the servo amplifiera)
increases amplifier stabilityb)decreases amplifier stabilityc) has
no effect
9. How is a push-pull transistor arrangement connected?a)
emitter to emitterb)collector to collectorc) base to base
10. Thermal runaway in a transistor is caused bya) excessive
heat causing maximum current flowb)excessive heat causing minimum
current flowc) low heat causing minimum current flow
1. A single integrated circuit Op Amp has how many pins?a)
4b)7c) 8
2. What is the output of the amplifier shown below?a) 0Vb)3Vc)
5V
3. A thyristor is commonly used fora) voltage
regulationb)overvolts regulationc) rectification
4. A diode which emits photons when conducting is aa)
zenerb)varactorc) light emitting
5. Avalanche breakdown occurs whena) forward bias becomes
excessiveb)forward bias exceeds a certain valuec) reverse bias
exceeds a certain value
6. The electrodes of an SCR area) anode, cathode,
sourceb)source, drain, gatec) gate, cathode, anode
7. What gives an LED its colour?a) A gasb)The coverc)
Composition and impurity of the compound
8. For conduction of a transistor the emitter junction isa) fwd
biasedb)reverse biasedc) fwd or reverse as appropriate to the input
signal
9. In a PNP transistor which way does conventional current
flowa) base to emitterb)collector to emitterc) emitter to
collector
10. Infinite gain, infinite input impedance & zero output
impedance ischaracteristic of aa) Class A ampb)Class B ampc) Op
amp
1. Forward voltage of a silicon diode isa) 0.6Vb)0.2Vc) 1.6V
2. An advantage of a common emitter isa) it is a voltage
followerb)it has high power gainc) it has high voltage gain
3. What amplifier is biased at cut offa) Ab)Bc) C
4. When testing a transistor with an ohmmeter, what is the
resistance ofthe emitter/collector?a) High resistance one wayb)High
resistance both waysc) Low resistance both ways
5. What is the typical volts drop across an LEDa) 1.6Vb)0.2Vc)
0.4V
6. What diode gives off light photons when forward biaseda)
LEDb)Shottky diodec) Gunn diode
7. A logic circuit with more than one gate will havea) one of 2
states of logic outputb)2 or more outputsc) an analogue output
9. In a synchro, what is used to convert signals from one form
toanother?a) Transmitterb)Transducerc) Transformer
10. Components on an integrated circuit area) in the
solidb)don't need themc) on the surface
1. What diode is used to stop power spikes in a coil?a) Two
directional zener diodeb)Shottky diodec) Gunn diode
2. The anode of a diode is connected to a +4v DC supply and the
cathodeis connected to a +2v DC supply. The diode isa) forward
biased not conductingb)reverse biased not conductingc) forward
biased conducting
3. Using electron flow in a diode the current flows froma) Anode
to Cathodeb)Cathode to Anodec) Cathode to Base
4. A control surface position feedback signal isa) proportional
to surface positionb)inversely proportional to surface positionc)
non-linear
5. In a PNP transistor, conventional current will flow whena)
the emitter is more positive than the baseb)the base is more
positive than the emitterc) the collector is more positive than the
emitter
6. An E&I transformer out of datum hasa) equal and opposite
voltages in each windingsb)unequal and opposite voltages in both
windingsc) no voltage in either winding
7. A gyro will providea) rate feedbackb)velocity feedbackc)
positional feedback
8. In a common collector circuit the output and input area) out
of phase by 90ob)in phasec) out of phase by 60o
9. In velocity feedback the signal isa) in phaseb)out of phasec)
equal to the error signal
10. When a hole diffuses from the p region to the n regiona) it
becomes a minority carrier in the n regionb)lowers the potential
barrierc) raises the potential barrier
__________________Homer not function well beer without !
Module 4 iii
1. The junction barrier offers opposition to onlya) holes in the
p-regionb)free electrons in the n-regionc) majority carriers in
both regions
2. An increase in velocity feedback willa) decrease the speed
the load movesb)increase the speed the load movesc) have no effect
on speed
3. A two phase motor will stop whena) the reference phase is
reversedb)the control phase is reversedc) the control phase is
zero
4. A tachogenerator output isa) variable frequency, constant
voltageb)variable voltage, constant frequencyc) variable frequency,
variable voltage
5. Rate feedback can be obtained from aa)
synchrob)tachogeneratorc) potentiometer
6. Positional feedback can be obtained from aa)
synchrob)tachogeneratorc) potentiometer
7. The frictional force in a servomechanism that is proportional
tospeed is calleda) stictionb)coulomb frictionc) viscous
friction
8. The 'null' point in a control synchro is when the two rotors
area) at 90o to each otherb)parallel to each otherc) wired in
series
9. If two of the stator leads are cross connected in a control
synchrosystem, a 25o clockwise rotation of the input rotor would
result in theoutput rotora) moving 25o clockwiseb)moving 25o
anticlockwisec) moving 180o to rectify the defect
10. Damping in a servomechanism is easier to apply ifa) the
mechanism is light and has low inertiab)the mechanism is heavy and
has high inertiac) the mechanism is light and has high inertia
1. Reverse biasa) lowers the potential barrierb)raises the
potential barrierc) greatly increases the majority carrier
current
2. If the electrical connections to the feedback generator in a
controlsynchro system were disconnected, thea) motor would run in
the wrong directionb)input signal to the amplifier would reducec)
system would tend to oscillate
3. An increase in servo amplifier gaina) reduces the speed of
the systemb)increases system responsec) reduces tendency to
hunt
4. In a control synchro the stator current ceases to flow when
thea) CT rotor is at nullb)two rotors are alignedc) power is
removed
5. The term 'velocity lag' refers to aa) speed errorb)position
errorc) acceleration error
6. The rotor of an AC tachogeneratora) has skewed slotsb)has a
copper, brass or aluminium cylinderc) rotates at constant speed
7. A servo system with transient negative velocity feedbacka) is
damped with little velocity lagb)is damped with high velocity lagc)
is underdamped with high velocity lag
8. To reverse the direction of rotation of a two phase induction
motora) reverse the polarity of the control phaseb)reverse the
polarity of both the control phase and reference phasec) shift the
reference by 90o
9. In a rate servo (speed control) the signal into the servo
amplifierisa) input voltage plus tachogenerator outputb)input
voltage minus tachogenerator outputc) input voltage plus position
feedback voltage
10. Loss of DC to a servo amplifier causes the motor toa) run
continuouslyb)stopc) reverse
1. Avalanche breakdown occurs whena) forward current becomes
excessiveb)forward bias exceeds a certain valuec) reverse bias
exceeds a certain value
2. An AC servo demand can be converted to drive a DC motor by
theintroduction of aa) rectifierb)modulatorc) demodulator
3. Synchro indicator systems are used when the indication is
required tomovea) a fraction of the input distanceb)slower than the
input ratec) at the same rate as the input
4. A linear variable differential transformer is used to
measureposition feedback wherea) 360o of rotation and high angular
accuracy is requiredb)accuracy is of limited importance but robust
construction andreliability is importantc) an output whose phase is
related to direction of movement andamplitude linear over a wide
range
5. A low frequency sinusoidal input will cause a closed
loopservomechanism load toa) move to a demand position with no
overshootb)move backwards and forwards at the input frequencyc)
move to the demand position and then return to the datum
positionwithout any overshoot
6. To reduce oscillations about a demand positiona) the amount
of velocity feedback would be decreasedb)the amount of velocity
feedback would be increasedc) the amount of position feedback would
be increased
7. If a servo amplifier is suffering from drifta) the load would
move to a new position, proportional to the drift andstay
thereb)the load would move to a new position, proportional to the
drift andthen return back to the datum positionc) the load would
oscillate about the datum position
8. In a transient velocity feedback circuit, the tachogenerator
outputis summated with the demand voltagea) only when the load is
slowing downb)at all times when the load is movingc) only when the
load is speeding up or slowing down
9. Positive feedback applied to a servomechanisma) decreases the
response of the systemb)opposes the demand signalc) increases the
response of the system
10. A differential synchro rotor consists ofa) one winding
parallel to the transmitter rotorb)two windings at 90o apartc)
three windings at 120o apart
1. A differential synchro transmitter used for addition hasa)
the TDX S1 and S3 connections cross connected to the TXb)the TDX S1
and S3 connections cross connected to the TRc) the TDX R1, R3 and
S1, S3 connections cross connected to the TX
2. If forward bias is increased from zero on a p-n junction, a
rapidincrease in current flow for a relatively small increase in
voltage occursa) only after the forward bias exceeds the potential
barrierb)when the flow of minority carriers is sufficient to cause
an avalanchebreakdownc) when the depletion layer becomes larger
than the space charge area
3. An LVDT hasa) an output winding which is wound in series
oppositionb)an input winding whose voltage will change with load
movementc) an output winding whose voltage and frequency is linear
to loadangular movement
4. A diode connected across a relay coil is used toa) allow the
coil to energize with only one polarityb)cause a delay in switching
onc) dissipate coil spikes on switch off
5. Differential transmitters are used toa) add or subtract two
electrical signalsb)add or subtract a mechanical signal to an
electrical synchro signalc) increase the operating speed of the
synchro receiver
6. To convert a differential synchro from subtraction to
addition youwoulda) reverse the reference phase supplyb)change over
two rotor and stator connectionsc) change over all three stator
windings
8. When resolving a Cartesian input to a Polar outputa) the
inputs are a shaft angle and a voltageb)the outputs are two
voltagesc) the inputs are two voltages
9. To check the forward resistance of a diode with a multimeter,
thelead connected to the positive terminal is put to thea)
anodeb)cathodec) either anode or cathode
10. A resolver synchro output is obtained from a rotor witha)
one single coilb)two coils at 90o to each otherc) three coils at
120o to each other
1. The input and output signals of a common emitter amplifier
area) equalb)out of phasec) in phase
2. The output of a resolver synchro isa) dependant upon the
position of the rotor onlyb)proportional to the speed of input
rotationc) a function of the rotor position and excitation
voltage
3. The rotor of an autosyn position indicating system isa) a
permanent magnetb)an electromagnetc) spring controlled
4. A band pass filter excludes frequenciesa) above the frequency
required onlyb)below the frequency required onlyc) above and below
the frequency required
5. The rotor of a magnesyn transmitter isa) a dc
electromagnetb)a permanent magnetc) an ac electromagnet
6. In general the accuracy of a synchro system increases if
thea) stator current is highb)stator current is lowc) rotor current
is high
7. Torque synchro systems are normally used when thea)
mechanical load is lowb)mechanical load is highc) system accuracy
is of extreme importance
8. In a resolver synchro the stator windings are electrically
disposedbya) 90ob)120oc) 180o
9. The induced signal in the output coils of the magnesyn
systema) de-saturates the soft iron coreb)damps the pointer
oscillationsc) is of a value of 800 Hz
10. The direction of the induced (secondary) magnetic field in a
synchrotransmittera) is 90o to the primary magnetic fieldb)in the
same direction as the primary fieldc) is in the opposite direction
to the primary field
Module 4 ii
8. Mechanical friction in a servo results ina) reduced
gainb)increased dampingc) increased inertia
9. The position feedback signal isa) in phase with the input
demand signalb)in anti-phase with the demand signalc) phase
advanced by 90o with respect to the input signal
10. A servo system that overshoots and oscillates isa) under
dampedb)over dampedc) critically damped
1. The power supply to a torque synchro system is connected toa)
the transmitter statorb)the transmitter rotor onlyc) the
transmitter and receiver rotors
2. If the rotor of the receiver in a torque synchro system was
preventedfrom aligning with the transmitter rotor, thena) the
transmitter rotor will turn to align with the receiver rotorb)the
receiver will overheatc) a high current will flow in the stator
windings
4. A zener diodea) stabilizes voltage at a predetermined
levelb)allows current to flow in one directionc) acts like a
switch
5. The common collector amplifier is sometimes called the
emitterfollower circuit becausea) the emitter current follows the
collector currentb)the emitter voltage follows the base voltagec)
the emitter voltage follows the collector voltage
6. In a toroidal resistance transmitter indicator system, the
powersupply is connected toa) the brushesb)the resistor slabc) the
rotor
7. When a servo has reached its null and stopped, the velocity
feedbackisa) zerob)maximum and anti-phasec) maximum and in
phase
8. The primary purpose of rate feedback in a positional servo
system istoa) ensure minimum response timeb)prevent excessive
overshootc) ensure system linearity
9. In an AC rate servo, a steady input will result in the
servomotora) oscillating about a new datumb)rotating at a constant
speedc) rotating to a new datum position
10. An E&I bar output at datum hasa) no induced voltage in
the secondary windingsb)an imbalance of voltages in the secondary
windingsc) equal and opposite voltages induced in the secondary
1. A non-inverting op-ampa) has a non-inverting input and an
inverting outputb)has an inverting input and a non-inverting
outputc) a non-inverting input connection only
2. Amplifiers may be classified asa) common emitter or common
collector amplifiersb)voltage amplifiers or impedance amplifiersc)
voltage amplifiers or power amplifiers
3. What is a shottky diode used for?a) Very high frequency
applicationsb)Stabilsationc) Rectification
4. The result of cross connecting two of the transmission leads
in a torque synchro system and then turning the rotor of the
transmitter 60oclockwise would bea) the receiver would move 60o
clockwiseb)the receiver would move 120o anticlockwisec) the
receiver would move 60o anticlockwise
5. The control windings of a two phase servomotor is supplied
with ACvoltage ofa) constant amplitudeb)variable phasec) variable
amplitude, variable phase
6. In a torque synchro that includes a differential synchro the
powersupply is connected toa) the transmitter rotor onlyb)the
transmitter and receiver rotors onlyc) all three rotors
7. A differential synchro rotor has a) three windingsb)two
windingsc) one winding
8. If the rotor of a control synchro sticksa) the system
huntsb)high current will flowc) the position feedback will
oscillate
9. With the reversal of the connections to the rotor of the
transmitterof a torque synchro, the position of the receiver rotor
will bea) unchangedb)changed by 120oc) changed by 180o
10. The application of a 'stick-off' voltage to a control
synchro servosystem isa) to overcome the effect of static
frictionb)to overcome the effect of viscous frictionc) to prevent
alignment to a false null
1. When removing a microprocessora) no damage is done by static
dischargeb)considerable damage can be done by static dischargec)
ensure the power is OFF to avoid static discharge
2. An amplifier can provide both voltage gain and current gain
when itis connected in thea) common base configurationb)common
emitter configurationc) common collector configuration
3. How do you increase voltage gain of an amplifier?a) decrease
base circuit biasb)decrease input resistancec) increase input
resistance
4. In a resolver synchro the stator windings are electrically
displacedbya) 90ob)120oc) 180o
5. A servo system may include a brake, an automatic trim system
is oneexample where a brake is used. The brake isa) applied during
trimming to prevent oscillations about the demandpositionb)applied
when trimming is complete to prevent stabilizer creep c) applied
during trimming to prevent servo runaway
6. A resolver synchro output is obtained from a rotor witha) one
single coilb)three coils at 120oc) two coils at 90o
7. In a control synchro the stator current ceases to flow whena)
the CT rotor is at nullb)when the two rotors are alignedc) when
power is removed
8. In a speed control servo system (rate control), the purpose
of thetachogenerator isa) to make the velocity proportional to
servo demandb)to make the deflection proportional to servo demandc)
to make it run at constant speed
9. The result of reversing the rotor connections to the receiver
of atorque synchro system is that the rotor positiona) is
unchangedb)is changed by 120oc) is changed by 180o
10. The rotor of a torque synchro indicator isa) supplied with
an excitation voltageb)short circuitedc) connected in series with
the transmitter stator coil
1. When a hole diffuses from a p-region to the n-region ita)
becomes a minority carrier in the n-regionb)lowers the potential
barrierc) raises the potential barrier
2. How are the pins numbered on an op-amp IC?a) counter
clockwise from the dotb)clockwise from the dotc) from left to right
from the dot
3. To increase the output of a servo amplifier, it is necessary
toa) reduce the tacho feedbackb)increase the tacho feedbackc)
increase the position feedback
4. Angular displacement of the control coils with respect to
thereference coils in a two phase induction motor area) 0o,
180ob)90o, 270oc) 90o, 120o
5. a two phase induction motor used in a servomechanisma) will
always require a starterb)is self starting under light loadsc) runs
with no slip
6. A servomotor having only a tachogenerator as a feedback
device willa) vary its speed with input error voltageb)have a
constant speed for any given input voltagec) null out at a position
dependant upon input error voltage
7. A hysteresis servo motor is used in a servomechanism
becausea) it has good starting characteristicsb)good speed/voltage
relationshipc) low inertia
8. The null position of a torque synchro system is whena) the TX
and TR rotors are parallel to each otherb)the TX and TR rotors are
90o to each otherc) the TX and TR rotors are 120o to each other
9. Reversal of two of the stator connections on a torque
synchroreceiver would causea) the transmitter to become the
receiverb)the output to move the same direction as the inputc) the
output to move the reverse direction to the input
10. An AC tachogenerator stator hasa) two windings 180o
apartb)three windings 120o apartc) two windings 90o apart
1. A junction diodea) has one p-n junctionb)is similar to a
vacuum diode but cannot rectifyc) can handle only very small
currents
2. When the rotor of an AC tachogenerator is stationary, the
rotor hasa) no circulating currentsb)low circulating currentsc) no
magnetic fields
3. The output of a tachogenerator should bea)
sinusoidalb)exponentialc) linear
4. With a constant input to a speed control servo, the servo
motora) moves to a certain positionb)moves at a constant speedc)
oscillates, but otherwise does not move
5. A closed loop servomechanisma) must only have position
feedbackb)must have both position and velocity feedbackc) can have
either position or velocity feedback
6. Critical damping in a servomechanism isa) the point which
allows just one overshoot before the load comes torestb)the amount
of damping that results in the load just not oscillatingc) the
critical damping required for the optimum damping of
theservomechanism
7. In a control synchro system the power supply is connected to
thea) transmitter rotor and amplifierb)receiver rotor and
amplifierc) transmitter and receiver rotors
8. Reverse rotation of a control transformer rotor can be caused
bya) connections between the transformer rotor and the amplifier
reversedb)connections to the transmitter rotor reversedc) short
circuit between two transmission lines
9. Velocity feedbacka) opposes the demand inputb)assists the
demand inputc) prevents dead space errors
10. Velocity lag can be decreased bya) introduction of an
integratorb)keeping the error detector (summing point) output as
low as possiblec) decreasing the coulomb friction in the system
Module 4 i
1. What gives the colour of an LED?a) The plastic it is encased
inb)The active elementc) The type of gas used inside it
2. A germanium diode is used fora) rectificationb)voltage
stabilizationc) modulation
3. Why is a diode put in parallel with an LED?a) To protect it
from ACb)So it will work only above a certain voltagec) So it will
work only below a certain voltage
4. When testing the forward bias of a diode with a multimetera)
the positive lead of the ohmeter is placed on the cathodeb)the
positive lead of the ohmeter is placed on the anodec) it does not
matter which terminal the positive lead of the ohmeteris placed
5. In an NPN transistor the P is thea) collectorb)basec)
emitter
6. The output of a tachogenerator isa) proportional to speed of
rotationb)proportional to positionc) proportional to
acceleration
7. AC power is supplied toa) torque receiver onlyb)torque
transmitter onlyc) both the torque receiver and torque
transmitter
9. How is a PCB protected after manufacture?a) With
non-conductive varnishb)With waxc) By conformal coating
10. A differential synchroa) can only be used as a
transmitterb)can only be used as a receiverc) can be used as either
a transmitter or a receiver
1. Which of the following describes the characteristics of a
Thyristor?a) High voltage handlingb)High current handlingc) High
power handling
2. A semiconductor doped with an element having a valency of 5
willproducea) an N type materialb)a P type materialc) either an N
type or a P type depending on what type ofsemiconductor material is
used
3. What are the ideal characteristics of an Op Amp?a) Infinite
gain, infinite input Impedance and infinite outputimpedanceb)Low
gain, infinite input Impedance and zero output impedancec) Infinite
gain, infinite input Impedance and zero output impedance
5. What gate does the following Boolean expression representF =
A.B.Ca) ANDb)ORc) NOT
6. What gate does the following Boolean expression representF =
A+B+Ca) NOTb)NORc) OR
7. To decrease the voltage gain of a common emitter amplifier
youwould increase the resistance in thea) base circuitb)collector
circuitc) emitter circuit
8. A resolver hasa) 2 coils on the rotor and 2 coils on the
statorb)3 coils on the rotor and 2 coils on the statorc) 2 coils on
the rotor and 3 coils on the stator
9. The 'null' point on a control synchro is when the two rotors
area) at 90o to each otherb)parallel to each otherc) wired in
series
10. A FET when compared to a junction transistor isa) low
impedanceb)high impedancec) current operated
1. What type of diode would be used to stop voltage spikes
across a coilof a relay?a) Gunn diodeb)Schottky diodec) Double
acting diode
2. A silicon diode, when compared to a germanium diode hasa) a
higher forward bias voltageb)less forward bias voltagec) the same
forward bias voltage
3. A zener diode is used fora) rectificationb)voltage
stabilizationc) modulation
4. A multi-layer PCB hasa) one layer on either sideb)two or more
layers on one or both sidesc) two or more layers connected in
series
5. When a servomotor overshoots after a step input and
oscillates it isa) over dampedb)under dampedc) critically
damped
6. The rotor of a desynn indicator isa) an electromagnetb)a
permanent magnetc) an AC magnet
7. The position feedback from a potentiometer isa)
anti-phaseb)in phasec) 90 degrees out of phase
8. A differential synchro hasa) 3 phase stator, 3 phase
rotorb)single phase stator, 2 phase rotorc) 3 phase stator, single
phase rotor
9. When a servomotor has stopped, the rate feedback from
atachogenerator isa) zerob)maximum and in phasec) maximum and
anti-phase
10. A tachogenerator is usually used fora) rate
feedbackb)angular feedbackc) position feedback
2. Differential synchros havea) a transmitter onlyb)a receiver
onlyc) a transmitter and a receiver
3. In an integrated circuit, the components are mounteda) by
means of wires connecting themb)by metal oxide filmc) by metal
screws
5. One characteristic of the emitter follower isa) low
resistance outputb)low current amplificationc) high voltage
amplification
6. A reduction from the optimum setting of the velocity feedback
in aservo loop could causea) low servo gainb)instabilityc) slow
response
7. In a torque synchro system, the power supply is connected
toa) the rotor windings of the transmitter onlyb)the rotor windings
of both the transmitter and receiverc) the stator windings of the
transmitter
8. The phase difference between the supplies of a two phase
inductionmotor isa) 180ob)90oc) 0o
9. To reduce overshoot errors in a synchroa) the system will
have position feedbackb)the system will have velocity feedbackc)
the gain of the amplifier is increased
10. A synchro transformer is used toa) derive an error voltage
from a synchro transmitter signal and ashaft positionb)obtain a 26
volt AC referencec) add the output of two synchro transmitters
2. Reversal of the complete power to a torque synchro system
willa) have no effectb)cause reverse rotation of the receiver
rotorc) displace the receiver rotor by 180o
3. The power supply to a torque synchro system isa) ACb)DCc) AC
or DC5. When a positive voltage is applied to the base of a
normally biasedn-p-n common emitter amplifiera) the emitter current
decreasesb)the collector voltage goes less positivec) the base
current decreases
6. An amplifier current gain will be slightly less than 1, but
itsvoltage gain will be high, if it is connected in thea) common
base configurationb)common emitter configurationc) common collector
configuration
7. An open loop system is one which hasa) no direct feedback
loopb)rate feedback loopc) position feedback only
Electrics
The DC generator main contactor is welded closed. The fault
indicated isa The generator failure warning light illuminatesb The
generator ammeter reading is highc# The aircraft generator
continues to rotate after the engine is shut down
The DC generator switch directly controls thea Generator fieldb#
Generator contactorc Generator warning light
Increasing the load on a permanent magnet generator willa Reduce
the terminal voltage by a large amountb# Reduce the terminal
voltage by a small amountc Increase the terminal voltage by a small
amount
The separately excited generator voltage isa Independent of
rotational speedb Controlled by the loadc# Controlled by the
separate supply
The series wound generators terminal voltage will, when below
saturationa# Increase with an increase in loadb Decrease with an
increase in loadc Decrease with a decrease in rotational speed
The shunt wound generator is normally starteda# Off loadb On
loadc Either of the above
The shunt wound generator is controlled by a variable resistance
ina Series with the armatureb# Series with the fieldc Parallel with
the armature
In a cumulative compound wound generator thea The series and
shunt fields oppose each otherb# The series and shunt fields assist
each otherc Voltage falls suddenly with an increase in load
Which generators are usually used on aircrafta Seriesb# Shuntc
Compound
Increasing the speed of an aircraft generator results in an
automatica# Field circuit resistance increaseb Field circuit
resistance decreasec Armature circuit resistance increase
In the shunt generator the field is supplied bya A separate
supplyb# The armaturec The load
The shunt generators voltage falls on load due to thea High
resistance of the fieldb Low resistance of the armaturec# Armature
volts drop
Which one of the following aircraft cables if heated excessively
could give off toxic fumesa Nyvinb Tersilc# Efglas
Which of the following cables is most flexible throughout its
temperature rangea# Efglasb Unifire Fc Tersil
Which of the following cables has a conductor of tinned copper
strandsa# Nyvinb Tersilc Efglas
A cable is marked Tersil 22 the 22 refers toa The current
ratingb# The American wire gauge of the conductorc The
current/weight ratio
To measure current in a circuit the ammeter is connecteda In
parallel with the loadb# In series with the loadc Across the power
supply
The resistance of an ammeter must bea High to create a large
volts drop across itb Low because the ammeter is in parallel with
the circuitc# Low to prevent volts drop across it
A volt meter may be used in a circuit to measurea EMF of the
supply onlyb Volts drop across loads onlyc# Both of the above
To measure voltage in a circuit a voltmeter is connecteda In
seriesb# In parallelc Only across the power supply
The resistance of a voltmeter must bea Low to provide a parallel
path for the circuit currentb# High so that little current passes
through itc Low to prevent overloading the circuit
The forces acting on a meter which moves the pointer over the
scale is calleda The controlling forceb The turning forcec# The
deflecting force
The force acting on a meter which returns the pointer to zero is
called thea# The controlling forceb The turning forcec The
deflecting force
The force acting on a meter which opposes the deflecting force
is called thea# The controlling forceb The turning forcec The
damping force
The damping force in a meter operatesa Only when the pointer is
stationaryb# Only when the pointer is movingc At all times whether
the pointer is moving or stationary
The damping forcea# Prevents oscillation of the pointerb Assists
the pointer to move over the scalec Returns the pointer to zero
In a moving coil meter the deflecting force is provided bya
Hairsprings which move the pointer towards full scaleb A soft iron
permanent magnetc# A current carrying coil pivoted in a permanent
magnet field
In a moving coil meter the deflecting forcea Decreases with an
increase of current through the coilb Increases with a decrease of
current through the coilc# Increases with an increase of current in
the coil
The controlling force in a moving coil meter is afforded bya
Single hairspring onlyb Taut bands onlyc# Either hairsprings or
taut bands
Hairsprings in a moving coil meter providea# A controlling force
and a method of electrical connections to the coilb The deflecting
and damping forcec Electrical connections to the coil only
In a moving coil metera The hair springs are permanently
attached at both endsb# The outer end of one spring is movable to
provide zero adjustmentc The hairsprings are movable at both ends
to provide full scale and zero adjustments
In a moving coil meter damping is provided bya# Electromagnetic
induction in the coil frameb An air or oil dashpotc By a system of
levers
When using a moving coil meter to measure current, as an ammeter
it is usual toa Connect a very high resistor in parallel with the
coilb# Connect a very low resistor in parallel with the coilc
Connect a very high resistor in series with the coil
The resistor used to extend the range of an ammeter is called aa
Variacb# Shuntc Multiplier
A moving coil ammeter has a FSD current of 1mA and a resistance
of 0.1k. The value of resistor required to extend the range of a
meter to read 100mA isa# 1 ohm approx.b 99 ohm approx.c 100 ohm
approx.
An external resistor used to extend the range of an ammeter
usually hasa Two connections onlyb Two voltage connections and one
voltage connectionsc# Four connections two for the meter and two
for the external circuit
An external resistor used to extend the range of an ammeter will
be marked witha The value of the resistor in ohmsb# Fullscale
current and millivolts dropc Fullscale current and its value in
ohms
A moving coil meter with a coil resistance of 100 ohms and a FSD
current of 1mA will when used as a voltmeter measure voltages
froma# 0-100mVb 0-1Vc 0-100v
The resistor used to extend the range of a moving coil voltmeter
is called aa Variacb Shuntc# Multiplier
The resistor used to extend the range of a moving coil voltmeter
is placeda In parallel with the coilb In series with the loadc# In
series with the coil
A 100mv voltmeter having a FSD current of 1mA and a coil
resistance of 100 ohms. The value of resistance required to extend
its range to 0-10V isa 990 ohmsb# 9900 ohmsc 9990 ohms
The differential cutout contacts are closed using thea# Voltage
coil onlyb Current coil onlyc Both voltage and current coils
The indication of a short circuit in the remote ammeter shunt is
that thea Generator fails to come onlineb Generator failure warning
light remains onc# Generator operates normally but the ammeter
reads zero
With a rising generator voltage in a DC generation system thea#
Undervolts relay closes before the differential relayb Differential
relay closes before the undervolts relayc Undervolts and
differential relays operate independently1. Inductance in a circuit
smoothes the: - Current.
2. An Increase in frequency in an inductive circuit will result
in:A decrease in current flow.
3. The symbol X means total:Reactance.
4. Two Equal voltages out of phase by 180 degrees would
equal:Zero.
5. At Resonance in an RCL circuit, total impedance equals
total:Reactance.
6. The Voltage vectors for a series resonant circuit are:One
single vector
7. In an Inductance at saturation, the impedance is :Zero.
8. A gas filled valve is recognised in a circuit diagram by
a:Black dot inside the symbol.
9. The RMS value of a sine wave is :0.707 x max value
10. An auto transformer has :One winding.
11. In an AC circuit, apparent power is calculated from :VI
12. The flux density in a B/H curve is represented by the :B
value.
13. Two in phase voltages may be represented by :Vector
sums.
14 Circuit power factor may be found by ;True power over
apparent power.
15. A lagging power factor may be improved by:Increasing the
capacitance.
16. In an isolating transformer, if the secondary current is
increased the primary current will :Increase.
17. To measure current in a circuit, how is the ammeter
connected?In series with the load.
18. What does a voltmeter measure?Both supply voltages and volts
drops across the circuit.
19. What is the resistance of an ammeter?Low to prevent a large
volts drop across it.
20. How is a voltmeter connected?In parallel.
21. What is the resistance of a voltmeter?High, so little
current passes through it.
22. What is the force acting on a meter, which moves the pointer
over a scale?Deflecting force
23. What force returns the pointer to zero?Controlling
force.
24. What force in a meter opposes the deflecting
force?Controlling force.
25. When does the damping force in a meter operate?Only when the
pointer is moving.
26. What does the damping force do?Prevents oscillation of the
pointer.
27. In a moving coil meter, what is the deflecting force
provided by?A current carrying coil pivoted in a permanent magnetic
field.
28. In a moving coil meter, what does the deflecting force
do?Increases, with an increase in current through the coil.
29. In a moving coil meter, the deflecting force is :Greatest
when the indicator reads full scale.
30. The controlling force in a moving-coil meter is provided
by:Either hairsprings or taught bands.
31. What do hairsprings in a moving-coil meter provide?A
controlling force and method of electrical.
32. In a moving coil meter, which is true?The outer end of one
spring is movable to provide a zero adjustment.
33. The hairspring in a moving-coil meter:Provides a zero torque
when the pointer is at zero.
34. In a taught band moving-coil meter, the bands provide?A
controlling force, and a method of electrical connection to the
coil.
35. How is mechanical zero in taut band moving-coil meters
achieved?Twisting one of the fixed mounts of the bands.
36. In a moving-coil meter, how is damping provided?Electro
magnetic induction of the coil frame.
37. When using a moving-coil meter to measure current, how can
larger currents be measured?By connection a very low resistor in
parallel with the coil.
38. What is the resistor used to extend the range of an ammeter
called?A shunt.
39. A moving-coil meter has an FSD current of 1 mA and a coil
resistance of 100 ohms, what value resistor would be used to extend
the range to read 100 mA?1 ohm (approx.)
40. An external resistor used to extend the ammeter range
usually has:Four connections, two for the meter and two for
external circuit.
41. An external resistor used to extend the ammeter range will
be marked with:Full-scale current and millivolts drop.
42. Damping is normally achieved by?Eddy currents in the coil
and coil former.
43. A MCM with a coil resistance of 100 ohms and a FSD current
of 1mA, will when used as a voltmeter measure?0-100mV
44. What is the resistor used to extend the range of a moving
coil voltmeter called?Multiplier.
45. How is a resistor used to extend the range of a moving coil
voltmeter connected?In series with the coil.
46. A 100 millivolts voltmeter having a FSD current of 1mA and a
coil resistance of 100 ohms, what is the value of the resistance
required to extend its range to 0-10V?9900 ohms
47. A voltmeter with a low ohm per volt rating will do which of
the following?Indicate a value lower than the actual volts drop
being measured.
48. How is the ohm per volt rating of a voltmeter calculated?By
dividing the FSD current into one Volt.
49. When using a MCM to measure ac which of the following is
correct?A rectifier must be used to change the ac to dc.
50. When using a MCM to measure ac values:The meter measures
average values but is scaled to read RMS
51. To extend the range of an ac MC voltmeter :Step up/down
transformers may be used.
52. What does a thermo-junction meter consist of?A MCM and a
thermo-couple.
53. A thermo-junction meter may be used to measure?ac or dc.
54. What is a thermo-couple?A junction of two different metals
which when heated produces an emf.
55. A thermo-junction meter when used to measure ac :Measures
and indicates rms values.
56. The scale on a thermo-couple meter is?Square law.
57. How is damping in a moving-iron meter usually carried
out?Air dashpot.
58. A MIM may be used to measure?ac and dc.
59. How is the deflecting force of a MIM
provided?Electromagnetic induction.
60. How is the controlling force acting in a MIM provided?Hair
spring.
61. How may the scale of a MIM be made almost linear?By shaping
the iron pieces.
62. When using a tong test ammeter:The circuit need not be
broken.
63. An electrostatic voltmeter may be used for?ac or dc.
64. An electrostatic voltmeter has?Low loading effect on a
circuit.
65. A simple ohmmeter may be used to?Measure continuity and
unknown resistance values.
66. Before using a simple ohmmeter?The test leads should be
shorted together and the indicator set to zero.
67. The internal circuit of a simple ohmmeter consists of?A
moving coil meter in series with a battery and a variable
resistor.
68. Test meters designed to check insulation resistances are
often called?Meggers.
69. Very low resistance measurements such as metal to metal are
made with?Bonding testers.
70. A ratiometer movement is used in?Meggers and bonding
testers.
71. What provides the deflecting force in ratiometer movements?A
current carrying coil in a permanent magnetic field.
72. What provides the damping force in ratiometer movement?Eddy
currents in the coils and formers.
73. The voltage out put of a megger used on aircraft
is?250V.
74. What is the voltage output of a safety ohmmeter?Max 30V but
regulated by the current flowing.
75. What is the out put voltage of a 500V megger?Dependant on
rotation speed of handle.
76. What is the scale reading on a 500V megger?Non-linear from
zero to infinity.
77. What does a 500V megger consist of?A hand cranked generator
and a ratiometer movement.
78. The cranking handle should be turned at what speed?160
rpm.
79. The out put voltage of a 250v megger is?Limited to 250V
above 160 rpm
80. What is the scale reading on a 250V megger?Non-linear from
zero to infinity.
81. A 250V megger consists of a hand cranked generator and?A
ratiometer movement, smoothing circuit and voltage limiting
circuit.
82. What is the purpose of the silicon-carbide disc in the 250V
megger?To act as a voltage regulator.
83. Safety ohmmeters are used on circuits under which
conditions?The testing current must not exceed a specified
value.
84. What are typical values for maximum voltage and current in
safety ohmmeters?30V and 10 mA.
85. The armature winding in a safety ohmmeter is?High
resistance.
86. What does a bonding tester do?Measures resistance values
from 0 to 0.1 ohms.
87. Where does a bonding tester get its power from?Internal
NiCad cell.
88. Frequency meters a generally designed to measure?A small
range of frequencies.
89. What is the purpose of an oscilloscope?To measure waveform
and voltage.
90. What part of an oscilloscope gives visual display?A CRT.
91. What is the maximum resistance between the main earth system
and earthing device?10 megohms.
92. What is the primary purpose of bonding metallic parts on an
aircraft?To prevent high potential differences building up between
metallic parts.
93. Why does a primary bonding connection have a large
cross-sectional area?To maintain the same potential through
out.
94. In what order do you carry out the three main electrical
checks?Bonding, Continuity, Insulation.
95. What is the minimum recommended bonding resistance between
extremities of an airplane?0.05 ohm.
96. When an engine is not in direct contact with its mounting,
how should it be bonded?With at least two primary conductors, one
each side of the engine.
97. When carrying out a pre use check on a bonding tester,
shorting the three prongs on both probes?Should give a zero
reading.
98. When an earth-return terminal assy. has been replaced, what
checks required?Bonding and milli-volts drop tests.
99. If a bonding testers leads are damaged, what must you do?The
leads and tester must be returned to the manufacturer, for repair
and re-calibration.
100. When carrying out a bonding test on a current carrying
earth terminal, what should the recommended resistance not
exceed?0.025 ohm.
101. When carrying out a milli-volts drop check, what is the
approximate guide for a correct reading?5 milli-volts drop for
every 10 amps flowing.
102. When refuelling an aircraft why must the aircraft and
tanker be bonded together?To maintain both at the same electrical
potential.
103. When carrying out a continuity test on a circuit where a
known resistance exists, what instrument would you use?A multi
meter
104. Effective continuity is not possible unless?The portion of
the circuit under test must constitute a simple series circuit,
with no parallel paths.
105. Why is a low voltage supply used for continuity testing?To
avoid breaking down any high resistance films that might exist
between contacting surfaces.
106. If an insulation resistance tester is operated with the
leads suspended in free air, what will the meter read?Infinity.
107. When replacing a bonding connection and the original cannot
be matched, what would you use?One manufactured from the same type
of material, but of greater cross section area.
108. How do we reduce or remove electrostatic charges on fibre
glass surfaces?The surface is treated with special conductive
paint.
109. If bridging strips or bonding cords are fractured, what
action?Repalcement.
110. How is the accuracy of a bonding tester checked?Use it to
measure the resistance of three standard test resistors.
111. An insulation test is carried out on a group of cables, and
a low reading obtained, what action?Break down the circuit and
carry out further checks.
112. What is a typical minimum insulation resistance value for
an U/C bay?2 megohms.
113. Whenever possible, a functional test should be carried out
on an A/C using?An external supply.
114. Immediately after carrying out an insulation check what
should you do?Note the readings and atmospheric conditions, and
compare to previous reports.
115. How is an AVO zeroed on the ohms range?By using the
variable resistor.
116. A device that converts a physical quantity into a
corresponding electrical signal is called?A Transducer
117. Electrons in an atom orbit the nucleus in shells, the one
nearest the nucleus is called?K shell.
118. The maximum number of electrons this shell can contain is?2
electrons.
119. These orbits taken by electrons are energy levels. An
electron in the K shell will have?Less energy then the L, M, N
shells.
120. The unit used for energy level is?The ampere hour.
121. For an electron to move from one level to another, there
must be?A vacant position into which it can move.
122. The highest occupied shell of and atom is called its
?Valence shell.
123. Materials that behave as insulents at very low temperature,
and conductors at high temperatures are called?Intrinsic
semiconductors.
124. When electrons are shared by atoms they form?Covalent
bonds.
125. Materials such as germanium and silicon where four covalent
bonds are formed, are called?Tetravalent elements.
126. Adding a small amount of impurity element to a crystal of
intrinsic semiconductor material, is called?Doping.
127. An N-type intrinsic semiconductor is?Electrically
neutral.
128. An N-type intrinsic semiconductor has been doped with?A
donor impurity.
129. Positive holes are created by doping an intrinsic
semiconductor with?A trivalent impurity.
130. In N-type materials the majority carriers
are?Electrons.
131. In P-type material the minority carriers are?Elecrons.
132. A method to determine whether the majority carriers are
holes or electrons in a semiconductor is to make use of?The Hall
effect.
133. In a P-N junction the area around the junction is know
as?The depletion layer.
134. The usual method of making connections to semiconductor
devices is by?ohmic contacts.
135. In a junction diode the depletion layer will disappear if
the?Junction is fwd biased.
136. When a junction diode is reversed baised, any current flow
will be due to?Minority carriers.
137. Diodes that are designed to operate in a reverse bias
direction are known as?Zener diodes.
138. A transistor is a semiconductor that can be used
for?Amplification.
139. The regions of a transistor are called?The base, collector
and emitter.
140. In order to achieve emitter-collector current, the
base-emitter junction must be?Forward-biased.
141. The initials FET stand for?Field Effect Transistor.
142. In FET's the regions are designated?The source, Drain and
Gate.
143. Current flow in an FET is controlled by?Gate voltage.
144. An FET operating in depletion mode will, if the source and
drain are connected to the supply?Will be normalyconducting???
145.An FET operating in the enhancement mode, will if connected
to the supply be?Not normally conducting.
146.A silicon controlled rectifier (SCR) is a type
of?Thyristor.
147.A triac can be used?Only on ac circuits.
148. In a uni junction transistor, if the emitter junction is
reverse biased , it acts as?A simple potential divider.
1. An increase in plate area will increase battery?Capacity
2. If the SG in one cell of a 24V Lead battery is low?That cell
is U/S
3. If the insulation resistance of a lead battery is down, it
indicates?Case Leakage
4. Temperature correction of the SG reading of a lead battery
is?+0.001 for 2.5F
5. The actual capacity of a battery can be obtained by?The rate
of discharge graph
6. A capacity test is required every?3 months
7. The life of an aircraft battery is?Until it fails the
capacity test.
8. The capacity of a battery would maintain electrical services
for a minimum of?30 Mins.
9. Battery connections should?Be smeared with petroleum
jelly
10. If two 12V 40AH batteries are connected in series, the
capacity would be?24V 40AH
11. If a Lead acid battery is stored longer than 2 weeks it will
require?A freshening charge.
12. The nominal voltage for a lead cell is?2V.
13. The electrolyte in a NICAD is?Potassium Hydroxide.
14. The SG of the electrolyte in a nicad cell on discharge?Stays
constant.
15. Nicads are topped up?At the end of a charging cycle
16. To determine the state of charge of a nicad battery?A
measured discharge test must be carried out.
17. Spilled nicad elecrolyte is neutralised by?Boric acid
18. The plate materials in a fully charged nicad cell
are?Negative plate cadmium, positive plate nickel hydroxide.
19. The expected spring tension on the brushes of a 6 kw dc geny
would be?32 ozs.
20. Excessive brush sparking is caused by?Low brush spring
pressure.
21. The windings embedded in the pole faces of a geny
are?Compensating coils.
22. An indication of good commutation on a dc machine would
be?Little or no sparking at the commutator.
23. A dc machine is cleaned using?Trice on the windings.
24. The bedding of brushes on dc apparatus?Must never be done on
the aircraft.
25. The voltage regulator on a singled engined aircraft can?Be
trimmed for voltage only.
26. Load sharing on a dc generation system is achieved
by?Circulating currents affecting the carbon pile for voltage
trimming.
27. If compound dc generators are operated in parallel, they
must?Have an equalising or load sharing loop.
28. During regulation and load sharing checks, the genys output
voltage is determined using?
29. Dc load share adjustment is carried out with?All genys on
line on load
30. After overhaul of a dc machine, and insulation check must be
carried out when?After function check while the machine is still
warm.
31. The insulation/resistance of a dc motor would be?Lower than
the supply lines.
32. An actuator is an elecro-mechanical device comprising?Split
field, series windings,a brake, internal limit switches.
33. While an actuator is travelling, the position of the limit
switches are?Both open and closed are closed
34. if an actuator brake coil is open circuit, the actuator
will?Stop.
35. A suppressor in a dc geny is used to suppress?Radio
interference.
36. An open circuit on a lap machine would cause
excessive?Sparking
37. The expected rpm of a dc geny would be?6000 rpm
38. With a voltage regulator in situ you can?Adjust voltage
trimming.
39. The equalising coil in a carbon pile regulator?Is connected
in series with the carbon pile
40. The ballast resistor in a carbon pile regulator is used
to?Stabilise the action of the regulator.
41. When making in- situ adjustments to a carbon pile regulator
the?Adjustments are made when the pile is warm
42. A pilot relay and a differential relay are incorporated in a
dc geny control circuit?The pilot operates before the differential
relay.
43. The differential cut out contains a?Differential and series
coil.
44. The RCCO will operate ?After the differential relay.
45. When a dc generator fails, the pilot will receive the
following indications?Zero current on the ammeter, and a red
PFWL.
46. The PFWL will come on when the contacts of the?Over volts
relay opens.
47. The purpose of field flashing is to?Change the polarity of
residual magnetism in the field winding.
48. An over voltage is sensed by the?The voltage sensing coil
connected across the geny output.
49. The output stage of the voltage regulator for a dc generator
is a power transistor. It acts as?A switch.
50. The Tirill regulator is adjusted by?Varying the spring
tension.
51. Stabalising winding?Oppose the voltage coil when transients
occur.
52. Heave duty cable runs can be reduced by using?Heavy duty
relays.
53. Economy coils are?To allow a relay to be held on with a low
current.
54. AC relays?Have laminated armatures.
55. Slugged relays?Introduce a time delay in to circuit
switching.
56. A milli-volts drop test is carried out on a heavy duty
contactor with the contacts?Closed
57. In a fuse HRC means?High rupture capacity.
58. The current rating of a fuse indicates?Current that can be
carried without the fuse operating.
59. In an overload condition with a limiter in the circuit, the
limiter would?Allow the circuit to operate at over load for a short
time.
60. An aircraft should carry at least the following amount of
spare fuses?10% or 3..which ever is the greater.
61. A trip free cb can be expected to trip in under a minuet
with a load of at least?1.5 the rated value.
62. A trip free cb?Cannot be reset while the fault exists.
63. When the wite collar on a push pull cb is in view this
indicates?The cb is tripped
64. During a milli-volt drop test, the milli-voltmeter reads
150mV at 300A. Contact resistance is therefore?0.0005
65. If the aircraft generators are operating, ground power
must?Not be paralleled with the generators.
66. The small pin on the external power plug?Provides the hold
in supply for the ground power contactor.
67. When the battery contactor is closed, the aircraft volt
meter will read?24v.
68. The resetting type fire detector depends for operation upon
the?Co-efficient of expansion of a steel tube.
69. The least toxic extinguishers are?BCF
70. The correct type of extinguisher to be used in a fltdeck
is?Water glycol
71. The correct type to be used on an aircraft electrical fire
is?BCF
72. The head of and a/c extinguisher is tested for continuity
with?Safety Ohmmeter
73. A fire bottle insulation check is carried out between?All
three pins and earth.
74. An engine fire extinguisher over pressure is indicated
by?Bright red bowl.
75. Before electrically connecting an engine fire extinguisher,
you must?Carry out a no volts test on the connections.
76. When testing a fire detector you would use?A shroud or long
type heater.
77. The balancing cell in a smoke detector unit?Counteracts
differences in supply voltage.
78. When the detector test switch is operated it?Activates the
detecting cell
79. Zero adjustment of the detector is done by physically
varying the light?Received by the balancing cell.
80. In a photo electric type detector, the test function is
effected by?A lamp.
81. Serviceability of the visual indicator filament during test
is indicated by?The illumination of the green pilot light
window
82. Airconditioning systems must supply a minimum of?1.lb air
per person per minute
83. The torque of an aircraft starter motor is?High
84. To limit the stating current of an engine starter motor,
resistance is placed?Series with the armature.
85.The voltage of an ignitor plug on a gas turbine engine is
dependant on?Discharge gap.
86. The conductor in a tersil cable is?Nickel plated copper
87.A cable marked tersil 22, the number represents?Cross
sectional area.
88. If the cross sectional area of a conductor is increased,
resistance wil?Decrease proportionally.
89. Copper is inferior to aluminium when conducting in
comparason to?Weight.
90. The maximum bonding on an aircraft should be?0.05 ohms
91. If all three prongs of a bonding tester are shorted together
the reading would be?0.
92. The leads of a bonding tester are?Critical in length, and
resistance is catered for.
93. Before effecting a crimp the ends of the cables should
be?Lightly twisted in the direction of the lay.
94. The number of dots impressed on the insulation of a crimp
indicate?Correct tool was used for effecting the crimp.
95. Can the pressure of the insulation crimp jaws on a red/blue
pidg crimping tool be changed?Yes
96. AC feeder cables are twisted together to ?Reduce radio
interference.
97. The recommended distance between in line crimps is?10
inches
98. The insulation resistance in undercaridge bays should not
normally be less than?2 megohms.
99. Capacitive circuits should be disconnected when carrying out
an insulation check because the tester will?Give a falsely low
reading as the capacitor charges.
100. Circuit testing should be carried out in the following
order.Bonding,continuity,insulation,function.
101. To check the fwd resistance of a diode with an avo, the
positive lead should be put to the?Cathode.
102. After carrying a function test of a circuit, and the
circuit turned off?The fuse/cb should be tripped to check
isolation.
103. A 250 volt megger should not be used on?Electronic
equipment.
104. When conducting an insulation check?The conductors are
tested collectively and any suspect tested individually.
105. A heavy duty connection is tested by?Milli volt at rated
current.
106. To find a high resistance or open circuit, carry
out?Continuity test.
107. The primary of the voltage stabilising transformer senses
the out put of?Main TRU
108. A current transformer should always have its secondary
either connected or short circuited due to?A rise in higher
secondary voltage.
109. An inverter is used to convert?DC to AC
110. Anti icing mats are rated in?Watts/square foot.
111. A filament has the letters MES on its shaft, this
means?Minature Edison Screw
112. The life of a dc fluorescent light can be increased
by?Periodically reversing the supply.
113. The SI unit of luminous intensity is the?Candella.
114. Increase in temperature causes the fire wire capacitance
to?Increase.
115. The fire warning is cancelled by?Reducing the fire wire
temperature.
116. The outer casing of a fire wire is connected to?Earth.
117. If the fire warning light remains illuminated after release
of the test switch, this indicates?Low insulation of the fire
wire.
118. The test switch of a continuous loop fire detector gives
a?Continuity test.
119. In a paralleled ac generation system, load sharing is
for?Real and reactive load.
120. In a constant frequency ac system, real load sharing is
achieved by?Regulating the generator drive torque.
121. In a constant frequency ac system, reactive load sharing is
achieved by regulating?Voltage regulator.
122. Paralleling in ac constant frequency system is effected
by?Bus Tie Breakers.
In an ac parallel system the normal flt state of the Bus tie
Breaker is?Closed
In a non parallel system, the position is?Open
An advantage of a star connected genaration system over delta
wound is?2 potentials can be used.
Current in an inductive circuit will?Increase with a decrease in
frequency.
The GCR directly controls?Excitor field.
Tripping the GCR will?Trip the GCB and de-excite the
generator.
In a voltage regulation system, the current compounding
principal is?To increase total excitor field proportionally to load
current.
Using a pulsed width voltage regulation system, with an increase
in gen voltage?Pulse width decreases.
In a constant frequency ac system, the reactive load sharing is
achieved by?Generator excitation.
The magnetic trim coil of a CSD can modify the gen output drive
torque?When gen is operating in parallel on bus bar.
In a parallel ac generator system, load sharing is for?Real and
reactive loads.
The current in the active and reactive load sharing loop
is?Ac
In parallel ac system, real load sharing is achieved by
controlling?Generator drive torque.
Generator auto paralleling circuit controls the?GCB
The CSD speed trim solenoid is used to trim its speed?When the
geny is in parallel operation.
The load controller is used in?The real load sharing loop.A
mutual reactor is used in the?Reactive load sharing loop.
A mutual reactors output mainly depends on the
generator?Reactive load current.
Over excitation protection applies to?Parallel ac generation
systems.
Differential protection monitors for?Feeder cable faults.
The reactive load KVA is measured by the product of?B line
current and A-C line voltage.
Over voltage is a passive fault.
A rotary inverter uses?A dc compound motor.
The diodes in a TRU are connected in parallel?To reduce the
heating effect.
A rotating type field alternator is usually used on aircraft
systems.
A rotating field type alternator slip rings carry the?Field
current.
Decreasing the field current in an alternator will?Decrease the
out put voltage
A reistive load on an alternator, will?Reduce output
frequency
An inductive load on an alternator will?Reduce the terminal
voltage.
A stator rotating field applies to?Synchronous and induction
motors
Slip only applies to induction motors.
Which type of motor does not employ a squirrel
cage?Synchronous.
To improve the starting torque of an AC inductive motor
the?Rotor power factor is increased (resistance is increased)
A three phase ac motor has one phase disconnected while running,
this will?Have no effect on the running but it will not start form
stationary
In a synchronous motor the rotor is excited byD.C.
A 3 phase motor with star point earthed can have its direction
of rotation reversed by?Reversing any two phase connections.
An induction motor does not have its rotor connected to any
external source of power.
The terminal voltage decrease in an ac generator with increasing
resistive load is due to?Reactance and resistance.
The normal method of controlling an ac generators voltage is
to?Control the generators exciter current.
A basic ac synchronous motor cannot be self starting.
Increasing rotor resistance of an ac induction motor
will?Decrease normal running speed.
Brushless ac generator diodes are mounted in its rotor.
The salient pole rotor is used in?Synchronous ac generator.
A squirrel cage rotor will be found in?An induction motor
If a three phase induction motor will not star, it only growls
when on?It is probably a stator phase is open circuit.
During an insulation test on a 200 volt ac generator, the
minimum resistance expected ?1.3 megohms.
An ac generators power is rated as a ?Product of voltage and
current with a power factor.
The CSD/IDG governor speed control screw adjusts?Frequency.
The electrical trim control fitted to a CSD speed governor is
used to adjust?The output torque.
In a dc motor the armature current flow is?AC
In a dc motor, reversing field and armature connections
will?Still rotate in the original direction.
The purpose of a commutator in a dc motor is to?Reverse the
armature current.
Effective voltage = applied voltage - back EMF.
In a dc motor the MNA position is normally?Against the direction
of rotation.
Reactive sparking in a dc motor will occur if the brushes are
positioned on?The GNA
Decreasing armature current in a dc motor will?Decrease the
speed.
Copper losses in a dc motor are caused by?High resistance field
windings.
In a dc machine eddy currents occur in the ?Armature and field
pieces.
Laminated construction reduces eddy currents.
Each commutator segment in a dc machine has 2 coil
connections
Armature windings remain in place due to a wedge and strapping
around the armature
A lap wound armature is used for high current circuits.
A lap wound 8 pole dc machine has 8 brushes.
A wave wound armature dc machine has 2 brushes.
A wave wound machine is used for high voltage circuits.A 4 pole
dc machine, 1 rev is 4 pole pitches.
In a dc machine the polarity of an interpole is the same
polarity as?The last main pole in a dc motor.
Compensating windings ain a dc machine are located at?The main
pole pieces.
Armature torque is proportional to?Armature and field
strength.
Rotational speed of a dc motor is proportional to ?Armature and
field currents.
Increasing the voltage applied to th e armature
causes?Rotational speed to increase.
Reversing the supply to a permanent magnetic field motor will
cause?Direction reversal.
Rotational speed of a dc motor may be controlled by?Either field
or armature resistance.
The dc shunt motor has?Low starting torque.
To decrease the rpm of a dc shunt motor, the?Field resistance is
decreased.
Decreasing the field current of a dc generator will?Decrease
output voltage.
The purpose of the commutator in a dc generator is to?Convert
the generated ac to a rectified dc.
In a dc generator with armature reaction, the MNA moves?With the
direction of rotation.
In a dc motor, the MNA moves?With the GNA
Increasing the number of armature conductors in a dc generator
will?Increase induced EMF.
Compensator windings carry armature current.
Increasing the load on a PMG will?Reduce terminal voltage by a
small amount.
The series wound generators terminal voltage will?Increase with
an increase in load.
The shunt wound generator is normally started off load.
The shunt wound generator is controlled by variable resistance
in?Series with the field.
In a cumulative compound wound generator, the?Series and shunt
fields assist each other.
Shunt generators are mainly used on aircraft.
Minimum brush length is measured on the longest side.
A dc machine commutator is cleaned using lead free petrol.
The expected brush spring tension on a 6kw dc generator is?28 oz
to 36 oz.
Running a dc generator on no load for long periods will
cause?The commutator to glaze over.
The minimum insulation value on a 28V dc machine
is?0.5megohms
dc generator voltage is controlled using the ?Field
strength.
Before engine start the carbon pile is fully compressed.
The carbon pile in a voltage regulator is?Connected in series
with the generator field.
Transistor voltage regulators operate with pulse control.
The ballast resistor in a carbon pile regulator is selected
to?Set the correct ampere turns in the voltage coil.
The dc generator switch directly controls?The generator
contactor.
The differential cutout contacts are closed using the?Voltage
coil only.
Indication of a short circuit in the remote ammeter shunt is
that the?Generator operates normally but the ammeter reads
zero.
If a dc generator main contactor is welded closed, it becomes a
motor on shut down.The engine keeps turning while electricity is
supplied.
With rising generator voltage in a dc system the?Undervolt relay
closes before the differential relay.
In a dc system, the differential cut out contacts are closed
using?The differential coil only
The differential cut out opens using the?Series coil only
In a dc system, when reverse current flow is first detected,
initial action is?Differential contacts to open.
In this system, over volts condition is sensed by monitoring
the?The voltage of the field.
An over voltage condition will?De-excite the generator
(trip).
The differential cut out coil senses the difference in generator
out put and bus bar?When the undervolt relay is closed.
If the dc generator fault warning remains illuminated, while
indicating 28V it could be?The under volt relay has failed to
close.
The equalising coil in a carbon pile regulator?Modifies the
effect of the voltage sensing coil.
Load sharing in a dc system is achieved by?Changing the
generator field resistance.
Equalisation in a dc system, equalises the generators out put in
terms of?Power.
The voltage used to circulate the equalising current is
approximately?0.05 Volts.
With a vibrating contact type voltage regulator, overload
protection is achieved by?Limiting field current.
Engine starting system does not have to be protected against
reversed polarity.
The expected range of a dc generator speed is?5000 to 8000
rpm.
During load sharing adjustment on a dc system?A first grade
voltmeter is used.
Load sharing adjustments are carried out with?One generator at a
time on load.
The minimum insulation resistance you would accept on a 28V dc
generator is?0.2 megohm.
In a dc system, the normal range of a voltage trimmer is?3
volts
voltage adjustment on a dc system is carried out?With one
generator at a time off load.
On a dc system, load sharing is checked with?All generators on
load.
An open circuit voltage coil in a carbon pile regulator, wil
cause?Voltage increase to over volt condition.