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Question 1

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Question text

To test the accuracy of a kilowatt-hour meter an

electrician used a wattmeter. He found out that the

meter makes 5 revolutions in 18 seconds. The meter

constant is 3.2. What is the percentage error if the

wattmeter reading is 3368?

Select one:

a. 8% slower

b. 5% faster

c. 5% slower

d. 8% faster

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The correct answer is: 5% slower

Question 2

Incorrect



Question text

A magnetomotive force is supplied by a current of one

ampere through 100 turns. The magnetic circuit

consists of a steel core of 1000 permeability, 10 cm

long and 4 sq. cm area and an air gap one cm long.

What is the field intensity at the air gap?

Select one:

a. 100.53 oersted

b. 12.25 oersted

c. 497.66 oersted Incorrect

d. 124.4 oersted

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The correct answer is: 124.4 oersted

Question 3

Correct



Question text

A parallel plate capacitor is made of 350 plates,

separated by paraffin paper 0.0010 cm thick (k = 2.5).

The effective size of plate is 15 by 30 cm. What is the

capacitance of this capacitor?

Select one:

a. 140 uF

b. 70 uF

c. 15 uF

d. 35 uF

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The correct answer is: 35 uF

Question 4

Incorrect



Question text

To double the current range of a 50-micro-amp, 2 kilo-

ohm moving coil meter movement, the shunt

resistance should be

Select one:

a. 2 kilo-ohms

b. 1 kilo-ohm

c. 18 kilo-ohms Incorrect

d. 50 kilo-ohms

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The correct answer is: 2 kilo-ohms

Question 5

Correct



Question text

If an alternating voltage has a magnitude of 10 V at

30 degrees, what is its maximum voltage?

Select one:

a. 30 V

b. 40 V

c. 50 V

d. 20 V

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The correct answer is: 20 V

Question 6

Correct



Question text

A wire carries a current i = 3 cos 314t amperes. What

is the average current over 6 seconds?

Select one:

a. 0 A

b. 3.0 A

c. 0.532 A

d. 1.5 A

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The correct answer is: 0 A

Question 7

Correct



Question text

What is the flux density having a flux of 12,000

maxwells through a perpendicular area of 6 cm

squared?

Select one:

a. 2,000 gauss

b. 200 gauss

c. 72,000 gauss

d. 72 gauss

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The correct answer is: 2,000 gauss

Question 8

Correct



Question text

The result of capacitance C1 = 6 microfarads and C2

connected in series is 3 microfarads. Capacitor C2, in

microfarads is

Select one:

a. 3

b. 6

c. 8

d. 4

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The correct answer is: 6

Question 9

Correct



Question text

MERALCO used two wattmeters to measure the

balanced 3-phase dynatron elevator motor drive. The

coils of the wattmeters are connected to the current

transformers, which are lines 1 and 2 respectively.

The potential coils are connected to potential

transformers, which are across lines 2 and 3 and lines

3 and 1, respectively. The line potentials are 230 V

and the line currents are each 150 A. The wattmeters

each indicate 19.6 kW. Assume load is wye

connected. What is the total power supplied?

Select one:

a. 45.461 kW

b. 49.175 kW

c. 47.350 kW

d. 48.236 kW

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The correct answer is: 49.175 kW

Question 10

Not answered

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Question text

The torque of a spring controlled ammeter varies as

the square of the current thru it. If the current of 5

amperes produces deflection of 90 degrees, the

deflection in degrees for a current of 3 amperes is

____.

Select one:

a. 18

b. 32.4

c. 30

d. 54

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The correct answer is: 32.4

Question 11

Incorrect



Question text

A galvanometer has a resistance of 300 ohms. What

is the ohmic resistance to make it read one is to ten?

Select one:

a. 33.33

b. 30 Incorrect

c. 10

d. 100

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Question 12

Correct



Question text

Solenoid 25 cm long is wound with 200 turns, what is

the value of the field strength inside the solenoid,

when carrying a current of 2 amperes.

Select one:

a. 1000 AT/m

b. 1600 AT/m

c. 1400 AT/m

d. 1200 AT/m

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The correct answer is: 1600 AT/m

Question 13

Correct



Question text

If three 100-pf capacitors are connected in series,

then the total capacitance is

Select one:

a. 300 pF

b. 50 pF

c. 33.3 pF

d. 100 pF

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The correct answer is: 33.3 pF

Question 14

Correct



Question text

A sinusoidal voltage wave has an RMS value of 70.71

V and a frequency of 60 Hz. Determine the value of

the voltage 0.0014 second after the wave crosses the

wt axis.

Select one:

a. 70.71 V

b. 100 V

c. 50 V

d. 141.42 V

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Question 15

Incorrect



Question text

A 12 micro-farad capacitor charged at 500 Volts and a

6 micro-farad capacitor charged at 250 Volts are

connected in parallel. What is the potential difference

in the combination?

Select one:

a. 750 Volts Incorrect

b. 417 Volts

c. 500 Volts

d. 450 Volts

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The correct answer is: 500 Volts

Question 16

Correct



Question text

How long can a battery last with capacity of 50

ampere-hour running equipment of 5 amperes?

Select one:

a. 10 hours

b. 250 hours

c. 100 hours

d. 25 hours

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The correct answer is: 10 hours

Question 17

Correct



Question text

Two coils of inductances 4 H and 6 H are connected

in parallel such that their mutual inductance is 3 H

assists the self-inductance. The total inductance of

the combination is ____.

Select one:

a. 8.25 H

b. 2.06 H

c. 3.75 H

d. 0.94 H

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The correct answer is: 3.75 H

Question 18

Incorrect



Question text

Two parallel wires 10 cm apart carry current in the

opposite direction of 8 A. What is the magnetic field

halfway between them?

Select one:

a. 32 x 10^-6 T

b. 16 x 10^-6 T Incorrect

c. 8 x 10^-6 T

d. 64 x 10^-6 T

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The correct answer is: 64 x 10^-6 T

Question 19

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Question text

Two similar poles, each of 1 Wb, placed 1 m apart in

air will experience a repulsive force of

Select one:

a. 796 kN

b. 63 x 10^-3 N

c. 63000 N

d. 8 x 10^12 N

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The correct answer is: 63000 N

Question 20

Correct



Question text

If a body is considered as a conducting sphere of 0.5

m radius, its capacitance to infinity is

Select one:

a. 55 nF

b. 55 uF

c. 55 pF

d. 55 F

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The correct answer is: 55 pF

Question 21

Correct



Question text

A certain electric welder has a basic circuit equivalent

to a series RL with R = 0.1 ohm and L = 1 mH. It is

connected to an AC source e through a switch s

operated by an automatic timer, which closes the

circuit at any desired point on the 60 cycle, sinusoidal

wave e. Calculate the magnitude of the transient

current resulting when s closes as e is passing

through its peak value of 100 volts.

Select one:

a. 256.41 A

b. 76.32 A

c. 65.74 A

d. 80.54 A

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The correct answer is: 65.74 A

Question 22

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Question text

A 1% d Arsonval meter movement has coil and

swamping resistance adding to 200 ohms. The full-

scale voltage is 50 mV. Determine the shunt

resistance required producing 1 A full scale current

meter.

Select one:

a. 48.74 milli-ohms

b. 49.22 milli-ohms

c. 50.01 milli-ohms

d. 52.02 milli-ohms

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The correct answer is: 50.01 milli-ohms

Question 23

Correct



Question text

In symmetrical components, what is the vector sum of

1 + a + a^2?

Select one:

a. infinity

b. -1

c. 0

d. 1

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Question 24

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Question text

A 35 unit south pole is placed 1 inch to a 20 unit south

pole. Determine the force between the poles.

Select one:

a. 129.5, repulsion

b. 129.5, attraction

c. 108.5, attraction

d. 108.5, repulsion

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The correct answer is: 108.5, repulsion

Question 25

Incorrect



Question text

Twenty-four (24) dry cells are arranged in rows of six

(6) in series and the four (4) rows in parallel. The emf

of each cell is 1.40 Volt, and internal resistance of

each is 0.08 ohm. Determine the current to an

external resistor of 3.2 ohms.

Select one:

a. 2.53 A

b. 5.23 A

c. 5.32 A

d. 2.35 A

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Question 26

Correct



Question text

In an RL circuit, Kirchhoff law gives the following

relation: E = Ldi/dt + Ri where: E = supply voltage

(200 volts), R = resistance (20 ohms), L = inductance

(1 Henry), t = time in seconds, i = current in amperes.

If i = 0 when t = 0, find i when t = 0.02 second.

Select one:

a. 3.3 A

b. 3.2 A

c. 3.1 A

d. 3.0 A

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Question 27

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Question text

An electric heater carries 12 A at 110 V, is submerged

in 22.5 lbs of water for 30 minutes. What will be the

final temperature of the water if its initial temperature

is 35 degrees F?

Select one:

a. 133.56 degrees F

b. 135.43 degrees F

c. 125.42 degrees F

d. 128.33 degrees F

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The correct answer is: 135.43 degrees F

Question 28

Correct



Question text

A 6.0 H coil whose resistance is 12 ohms is

connected in series with a 24 ohms resistor and to a

144 V battery and a switch. The switch is closed at t =

0. Determine the energy stored in the magnetic field

at steady state.

Select one:

a. 46 J

b. 50 J

c. 52 J

d. 48 J

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The correct answer is: 48 J

Question 29

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Question text

A coil has 2500 turns and a current of 10 A flowing in

it produces an effective flux of 0.05 Weber. If the

resistance is 12 ohm, what is the time constant of the

coil

Select one:

a. 1.12 sec

b. 2.25 sec

c. 1.0 sec

d. 0.75 sec

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The correct answer is: 1.12 sec

Question 30

Correct



Question text

What is the size in square millimeter (mm^2) is the

cable of 250 MCM size?

Select one:

a. 126.675 mm^2

b. 132.348 mm^2

c. 118.656 mm^2

d. 112.565 mm^2

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The correct answer is: 126.675 mm^2

Question 31

Correct



Question text

An analog ohmmeter reads 18 on R X 10 k range.

What is the value of the measured resistance?

Select one:

a. 18 ohms

b. 18 kilo-ohms

c. 180 ohms

d. 180 kilo-ohms

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Question 32

Correct



Question text

An inductor draws 5 A of current at 110 volts, 60 Hz.

Determine the inductance.

Select one:

a. 56.38 mH

b. 58.36 mH

c. 38.56 mH

d. 53.68 mH

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The correct answer is: 58.36 mH

Question 33

Correct



Question text

If a force of 4.8 x 10^(-2) N is required to move a 40

uC charge in an electric field between two points 20

cm apart. What is the potential difference between

two points?

Select one:

a. 240 Volts

b. 360 Volts

c. 120 Volts

d. 160 Volts

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Question 34

Correct



Question text

Three resistors 10, 15 and 30 ohmic values are

connected in wye-configuration to a balanced 208 volt

three-phase supply. Calculate the total power of the

system.

Select one:

a. 2880 W

b. 3280 W

c. 3080 W

d. 2644 W

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The correct answer is: 2644 W

Question 35

Correct



Question text

A DC voltage of 80 volts is applied to a circuit

containing a resistance of 80 ohms in series with an

inductance of 20 Henry. Calculate the growth of

current at the instant of completing the circuit.

Select one:

a. 2 A/s

b. 1/4 A/s

c. 1/2 A/s

d. 4 A/s

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The correct answer is: 4 A/s

Question 36

Correct



Question text

Twelve similar wires each of resistance 2 ohms are

connected so as to form a cube. Find the resistance

between the two corners of the same edge.

Select one:

a. 1.167 ohms

b. 1.133 ohms

c. 1.102 ohms

d. 1.125 ohms

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The correct answer is: 1.167 ohms

Question 37

Correct



Question text

Determine the rms value of a semi-circular current

wave which has a maximum value of A.

Select one:

a. 0.23 A

b. 0.816A

c. 0.707A

d. 0.866A

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The correct answer is: 0.816A

Question 38

Correct



Question text

A current of 10 amperes at a power factor of 0.8

lagging is taken from 250 V a.c. supply. The reactive

power of the system is

Select one:

a. 1500 VAR

b. 2000 VA

c. 1500 watts

d. 2000 watts

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The correct answer is: 1500 VAR

Question 39

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What is the coefficient of coupling of two coils whose

mutual inductance is 1 H and whose self-inductances

are 1.2 and 2 H?

Select one:

a. 0.645

b. 0.912

c. 2.400

d. 1.549

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Question 40

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Question text

A magnetic coil produces 100,000 Maxwell with 2,000

turns and with a current of 2 A. The voltage is cut-off

and the flux collapses in 0.01 sec. What is the

average voltage that will appear across the coil?

Select one:

a. 20 kV

b. 2,000 kV

c. 2 kV

d. 200 V

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Question 41

Correct



Question text

A current transformer has a single turn primary and a

200 turn secondary and is used to measure a.c.

current with the help of a standard 5-A a.c. ammeter.

These arrangements can measure a line current of up

to ____ ampere,

Select one:

a. 40

b. 200

c. 1000

d. 5000

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Question 42

Incorrect



Question text

The stator of a 440 V, 50 HP shunt motor is tested at

75 degrees C for its insulation resistance between

terminals connected together and the ground frame.

When a 50,000 ohm voltmeter is connected in series

with a 600 V DC source, the meter indicates 125 V.

Calculate the insulation resistance.

Select one:

a. 190 kilo-ohms

b. 170 kilo-ohms

c. 200 kilo-ohms

d. 180 kilo-ohms Incorrect

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Question 43

Correct



Question text

An ammeter has a range of 0 - 10 amps. What is

shunt resistance to be connected if the range is

increased to 100 amps? The internal resistance of the

ammeter is 0.10 ohms.

Select one:

a. 2.111 ohms

b. 0.0111 ohms

c. 0.111 ohms

d. 1.111 ohms

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Question 44

Correct



Question text

A circuit draws 25 A when connected across a source

of frequency f1. Determine the current drawn by the

same circuit at resonance if f1 is half the resonant

frequency.

Select one:

a. 12.5 A

b. 50 A

c. 35.35 A

d. 17.68 A

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Question 45

Correct



Question text

A generator has a field winding with an inductance L =

10 Henry and a resistance Rf = 0.1 ohm. To break the

initial field current of 1000 amperes, the field breaker

inserts a field discharge resistance Rd across the field

terminals before the main contacts open. As a result,

the field current decays to zero according to the

differential equation. L*di/dt + i*R = 0, Where: R = Rf

+ Rd preventing a sudden decrease of i to zero, and a

resulting high inductive voltage due to L. Solve the

differential equation and determine the value of Rd

that would limit the initial voltage across it to 1,000

volts

Select one:

a. 0.95 ohm

b. 0.90 ohm

c. 0.85 ohm

d. 0.80 ohm

Feedback

The correct answer is: 0.90 ohm

Question 46

Incorrect



Question text

A capacitor is charged with 0.23 watt-second of

energy at a voltage of 48 volts. What is its

capacitance?

Select one:

a. 220 uF

b. 180 uF

c. 240 uF Incorrect

d. 200 uF

Feedbacks


Question 47

Correct



Question text

A magnet which generates 800 Maxwell of flux, is

inserted through a coil of 1000 turns. It is then

withdrawn within 0.15 sec. What is the voltage that

appears across the coil?

Select one:

a. 0.22 V

b. 533 V

c. 0.0533 V

d. 53.3 V

Feedback

The correct answer is: 0.0533 V

Question 48

Incorrect



Question text

Find the capacitance of a two plate capacitor of plate

area 12 sq. inch dielectric constant of 6 and dielectric

thickness of 0.01 inch.

Select one:

a. 1.6 nF

b. 1.5 nF

c. 1.2 nF Incorrect

d. 1.3 nF

Feedback

The correct answer is: 1.6 nF

Question 49

Incorrect



Question text

Four capacitors A, B, C and D are connected across a

15-V DC source. The charges accumulated in A, B

and C are equal to 2000, 750 and 1500 uC,

respectively. If the total capacitance of the

combination is known to be 35 uF, how much charge

is accumulated in capacitor D?

Select one:

a. 1000 uC

b. 1400 uC

c. 1200 uC Incorrect

d. 1500 uC

Feedback

The correct answer is: 1000 uC

Question 50

Incorrect



Question text

A power plant customer draws power at 220 volts

from transformers on a pole. Current transformers

with a ratio of 200/5 are used to meter the electrical

usage. What is the multiplier of the kW-hr and

demand meters?

Select one:

a. 40

b. 100

c. 200 Incorrect

d. 80

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A magnetic pole produces 5000 field lines. How much is the flux in Weber?

Select one:

a. 50 x 10^-6

b. 5 x 10^-6

c. 500 x 10^-5

d. 500 x 10^-6

Feedback

The correct answer is: 50 x 10^-6

The field winding of a DC generator is wound with 900 turns and has a resistance of 50 ohms. If the

winding is excited from a 240 V dc source, the magnetic flux linking the coil is 4 mWb. Determine the self-

inductance of the coil.

Select one:

a. 0.56 H

b. 0.83 H

c. 0.92 H

d. 0.75 H

Feedback

The correct answer is: 0.75 H

A copper disc of radius 0.1m is rotated about its centre with 20 revolutions per second in a uniform

magnetic field of 0.1 T with its plane perpendicular to the field. The emf induced across the radius of the

disc is

Select one:

a. 20pi millivolt

b. pi/10 volt

c. pi/20 volt

d. 10pi millivolt

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The correct answer is: 20pi millivolt

Twelve similar wires each of resistance 2 ohms are connected so as to form a cube. Find the resistance

between the two diagonally opposite corners.

Select one:

a. 1.28 ohms

b. 1.45 ohms

c. 1.66 ohms

d. 2.01 ohms

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The field winding of a separately-excited DC generator has an inductance of 60 H and a resistance of 30

ohms. The discharge resistance of 50 ohms is permanently connected in parallel with winding which is

excited from a 200 volt supply. Find the value of the decay current 0.60 sec after the supply has been

switched off.

Select one:

a. 1.12 A

b. 3.67 A

c. 3 A

d. 4.94 A

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The correct answer is: 3 A

Three 3.33 ohms resistors are connected in wye. What is the value of the equivalent resistors connected

in delta?

Select one:

a. 20 ohms

b. 10 ohms

c. 3.33 ohms

d. 6.67 ohms

Feedback

The correct answer is: 10 ohms

Two capacitors 30 and 10 microfarad are connected in series, what is the total capacitance?

Select one:

a. 20 microfarad

b. 7.5 microfarad

c. 300 microfarad

d. 40 microfarad

Feedback

The correct answer is: 7.5 microfarad

In a test of a 10-ampere watthour meter having a constant of 0.40, the disk makes 40 revolutions in 55

seconds. The average volts and amperes during this period are 116 volts and 10 amps. Determine the

percent accuracy of this meter at this load.

Select one:

a. 91.03%

b. 83.46%

c. 90.28%

d. 92.34%

Feedback

The correct answer is: 90.28%

A generator supplies three-phase power to balanced load. The voltage is 230 volts, the current is 18 A

and the power factor is 85%. What is the power?

Select one:

a. 3.6 kW

b. 1.4 kW

c. 1.6 kW

d. 6.1 kW

Feedback

The correct answer is: 6.1 kW

A certain 50 micro-A meter movement has a resistance of 90 ohms. What value of series multiplier is

needed to make an instrument that will read 5 volts (maximum)?

Select one:

a. 102 kilo-ohms

b. 110 kilo-ohms

c. 98 kilo-ohms

d. 99.91 kilo-ohms

Feedback

The correct answer is: 99.91 kilo-ohms

A voltage rise linearly from zero to 100 volts in 1 second, falls instantaneously to zero at t = 1 second and

remains zero thereafter. This voltage is applied to an RL series circuit in which R = 5 ohms and L = 100

mH. What is the current when t = 0.50 second?

Select one:

a. 9.60 A

b. 69 A

c. 6.90 A

d. 96 A

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The following are in series R = 1,000 ohms, L = 100 uH and C = 20,000 pF. The voltage across the circuit

is 100 V, 60 kHz. What is the total impedance expressed in ohms?

Select one:

a. 1885 ohms

b. 1882 ohms

c. 2132 ohms

d. 1000 ohms

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If an oscilloscope with a vertical deflection of 0.1 volt rms per centimeter (cm), is used in conjunction with

a 10 ohm shunt resistor to measure a 25 milli-amp current, compute the vertical deflection?

Select one:

a. 0.025 cm

b. 0.25 cm

c. 2.5 cm

d. 25 cm

Feedback

The correct answer is: 2.5 cm

Two equal resistances are connected in series across a certain supply. If the resistances are now

connected in parallel across the same supply, the power produced will be ____ that of series connection.

Select one:

a. four times

b. two times

c. one-fourth

d. one-half

Feedback

The correct answer is: four times

Three equal positive charges of 10 statcoulomb each are located at the vertices of an equilateral triangle

of 2 cm leg. What is the magnitude of the force acting on each charge?

Select one:

a. 12.5 dynes

b. 50 dynes

c. 43.3 dynes

d. 25 dynes

Feedback

The correct answer is: 43.3 dynes

A star-connected 400 HP (metric), 2000 V, 50 c/s motor works at a power factor of 0.7 lagging. A bank of

mesh-connected condensers is used to raise the power factor to 0.93 lagging. Calculate the capacitance

of each unit required if each is rated 500 V, 50 c/s. The motor efficiency is 85%.

Select one:

a. 302 uF

b. 225 uF

c. 194 uF

d. 233 uF

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A three-phase induction motor delivers 150 HP while operating at 80% efficiency and a power factor of

0.8 lagging from 480 V lines. A wye connected power factor correction capacitor is to be installed to

improve the overall power factor to 0.9 lagging. Determine the capacitance required per phase.

Select one:

a. 3850 uF

b. 1283 uF

c. 428 uF

d. 142.6 uF

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A 120 cm long conductor is carrying a current of 1.2 amperes and is situated at right angles to the field to

flux density of 0.65 Tesla. Calculate the force on the conductor.

Select one:

a. 1.587 N

b. 0.936 N

c. 1.348 N

d. 3.264 N

Feedback

The correct answer is: 1.587 N

Two point charges Q1 = 50 microcoulombs and Q2 = 10 microcoulombs are located at (-1, 1, 3) and (3, 1,

0) meters respectively. Find the magnitude of the force on Q1.

Select one:

a. 0.018 N

b. 4.9 N

c. 124.5 N

d. 74 N

Feedback

The correct answer is: 4.9 N

A magnetic circuit consists of silicon steel of 2000 permeability of 10 cm length and cross sectional area

of 22 sq cm and an air gap of the same cross section area and of 1 cm length. A one ampere current

flows through 500 turns of coil. Calculate the field intensity across the gap.

Select one:

a. 350 Oersted

b. 590 Oersted

c. 755 Oersted

d. 622 Oersted

Feedback

The correct answer is: 622 Oersted

A single phase circuit is supplied from a 220 volts 60 Hz source draws 2000 watts of power and 10

amperes current. What is the power factor of the circuit?

Select one:

a. 90.9%

b. 100%

c. 82.6%

d. 72.5%

Feedback

The correct answer is: 90.9%

A voltmeter using a 20 micro-amp meter movement has an ohm/V rating of

Select one:

a. 1 kilo-ohm/V

b. 10 mega-ohms/V

c. 50 kilo-ohms/V

d. 20 kilo-ohms/V

Feedback

The correct answer is: 50 kilo-ohms/V

The torque of a spring controlled ammeter varies as the square of the current thru it. If the current of 5

amperes produces deflection of 90 degrees, the deflection in degrees for a current of 3 amperes is ____.

Select one:

a. 18

b. 30

c. 54

d. 32.4

Feedback


Three (3) 10-uF capacitors are connected in series. What is the total capacitance?

Select one:

a. 60 uF

b. 6.66 uF

c. 3.33 uF

d. 30 uF

Feedback

The correct answer is: 3.33 uF

Three impedances Za, Zb and Zc are connected in parallel. If at 60 Hz, Za = j8, Zb = -j2 and Zc = 5 ohms.

Solve for the resultant power factor.

Select one:

a. 0.573 leading

b. 0.471 leading

c. 0.471 lagging

d. 0.573 lagging

Feedback

The correct answer is: 0.471 leading

Copper wire of certain length and resistance is drawn out to four times its length without change in

volume. What is the resistance of the bar?

Select one:

a. 16R

b. unchanged

c. R/16

d. 4R

Feedback

The correct answer is: 16R

An ammeter rated 5 A, having a resistance of 0.5 ohm, is to be converted into a 200-V voltmeter by

connecting a resistor in series with the ammeter. Calculate the value of this resistance.

Select one:

a. 37.4 ohms

b. 39.5 ohms

c. 35.5 ohms

d. 34.6 ohms

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To roughly check his kWh meter an electrician hook-up a wattmeter, he switched on the load, he counted

5 rev in 18 sec, the meter constant is 3.2. The wattmeter reads 368 Watts. What is the error of the meter?

Select one:

a. 8% slower

b. 5% slower

c. 5% faster

d. 8% faster

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The correct answer is: 8% slower

A 12 micro-farad capacitor charged at 500 Volts and a 6 micro-farad capacitor charged at 250 Volts are

connected in parallel. What is the potential difference in the combination?

Select one:

a. 450 Volts

b. 750 Volts

c. 417 Volts

d. 500 Volts

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An inductive coil having a resistance of 25 ohms and inductance of 0.2 H is connected in parallel with a

100 uF capacitor. Find the frequency at which the total current taken is in phase with the supply voltage.

Select one:

a. 29.5 Hz

b. 52.9 Hz

c. 46.5 Hz

d. 35.6 Hz

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The correct answer is: 29.5 Hz

An ammeter has a range of 0 - 10 amps. What is shunt resistance to be connected if the range is

increased to 100 amps? The internal resistance of the ammeter is 0.10 ohms.

Select one:

a. 0.111 ohms

b. 0.0111 ohms

c. 2.111 ohms

d. 1.111 ohms

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Four cubic meters of water is to be heated by means of four 1.5 kW, 230-V immersion heating elements.

Assuming the efficiency of the heater as 90%, determine the time required in boiling the water if the initial

temperature is 20 degrees C and if all four elements are connected in parallel.

Select one:

a. 69 hrs

b. 71 hrs

c. 66 hrs

d. 63 hrs

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The correct answer is: 69 hrs

A DC electromagnet is wound with 1000 turns of wire having a resistance of 30 ohms. When excited by a

voltage of 125 V, a magnetic flux of 2 mWb links the coil. What is the energy stored in the magnetic field?

Select one:

a. 8.34 J

b. 0.96 J

c. 4.17 J

d. 0.48 J

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The correct answer is: 0.48 J

A core of annealed steel sheet is wound with 1500 turns to wire through which a current of 40 mA is

flowing. If the length of the coil is 20 cm, calculate the magnetic strength is Amp-turns per meter.

Select one:

a. 350

b. 300

c. 450

d. 400

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How much time is required for electromagnetic energy to travel one nautical mile and return to the

source?

Select one:

a. 12.36 microseconds

b. 24.72 microseconds

c. 6.18 microseconds

d. 18.54 microseconds

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The correct answer is: 12.36 microseconds

Calculate the magnitude of the electric field at a point that is 30 cm from a point charge Q = -3.2 x 10^-6

C.

Select one:

a. 2.8 x 10^6 N/C

b. 3.2 x 10^6 N/C

c. 3.0 x 10^5 N/C

d. 2.4 x 10^5 N/C

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The correct answer is: 3.0 x 10^5 N/C

Four 3 pCoul spheres are in corners of square q 1 cm on sides. Find the force in Newton?

Select one:

a. 15.5 x 10^(-10)

b. 4.05 x 10^(-10)

c. 20.25 x 10^(-10)

d. 8.11 x 10^(-10)

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The correct answer is: 15.5 x 10^(-10)

The sequence components of phase a current are: Zero sequence current = 0.47 + j1.49, Positive

sequence current = 18.4 cis (-31.6 degrees), Negative sequence current = 3.23 cis (168.2 degrees).

Determine the phase b current.

Select one:

a. 18 cis 215 degrees

b. 19 cis 220 degrees

c. 20 cis 225 degrees

d. 15 cis 240 degrees

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The correct answer is: 18 cis 215 degrees

Two similar charges of 250 statC are situated on small spheres 15 cm apart. What is the potential at point

midway between the spheres?

Select one:

a. 25 statV

b. 16.7 statV

c. 66.7 statV

d. 33.3 statV

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The correct answer is: 16.7 statV

If a body is considered as a conducting sphere of 0.5 m radius, its capacitance to infinity is

Select one:

a. 55 nF

b. 55 uF

c. 55 pF

d. 55 F

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The correct answer is: 55 pF

A circuit consisting of three resistors rated: 10 ohms, 15 ohms and 20 ohms are connected in delta. What

would be the resistance of the equivalent wye connected load?

Select one:

a. 3.0, 4.0 & 5.0 ohms

b. 3.33, 4.44 & 6.66 ohms

c. 0.30, 0.23 & 0.15 ohm

d. 5.77, 8.66 & 11.55 ohms

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The correct answer is: 3.33, 4.44 & 6.66 ohms

Two wattmeters are connected are for the two wattmeter method with current coils in lines A and B of a

208 V, ABC circuit that has a balanced delta load. If the meter readings arte 6 kW and -3 kW respectively,

find the load impedance per phase.

Select one:

a. 8.18 cis (79.1 deg) ohms/phase

b. 18.8 cis (-35.2 deg) ohms/phase

c. 32.2 cis (36.2 deg) ohms/phase

d. 22.3 cis (-36.2 deg) ohms/phase

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The correct answer is: 8.18 cis (79.1 deg) ohms/phase

A moving coil instrument having meter resistance of 5 ohms is to be used as a voltmeter 0 - 100 volts. If

the full-scale deflection current is 10 mA, the required series resistance is

Select one:

a. 1000 ohms

b. 9995 ohms

c. none of these

d. 20 ohms

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Solenoid 25 cm long is wound with 200 turns, what is the value of the field strength inside the solenoid,

when carrying a current of 2 amperes.

Select one:

a. 1200 AT/m

b. 1000 AT/m

c. 1600 AT/m

d. 1400 AT/m

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The correct answer is: 1600 AT/m

A galvanometer with a 20-ohm coil resistance has a full-scale deflection current of 10 mA. If a 0.02 ohm is

placed across the meter to increase its capacity, what is the approximate new full scale current of the

meter?

Select one:

a. 10.01 A

b. 10.11 A

c. 11.01 A

d. 10.10 A

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Two incandescent lamps of 100 W, 200 V are in parallel across 200 V supply. The total resistance will be

____.

Select one:

a. 400 ohms

b. 800 ohms

c. 200 ohms

d. 600 ohms

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What is the force between a point charge 2 x 10^-5 coulomb and another 3 x 10^-6 coulomb when they

are 10 cm apart in vacuum?

Select one:

a. 45.5 kg

b. 53.95 kg

c. 5.395 x 10^-3 kg

d. 5.5 kg

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The correct answer is: 53.95 kg

The r.m.s. value of the complex voltage given by v = 16*(2^1/2) sin wt + 12*(2^1/2) sin 3wt is

Select one:

a. 192

b. 28*(2^1/2)

c. 20

d. 20*(2^1/2)

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The magnetic flux of 2000 lines is how many in maxwells?

Select one:

a. 8000

b. 1000

c. 2000

d. 4000

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What is 10^12 ergs/sec in kW?

Select one:

a. 100 kW

b. 10,000 kW

c. 1,000 kW

d. 10 kW

Feedback

The correct answer is: 100 kW

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