BEE 2123 SOALAN DALAM BAHASA INGGERIS Q1 ( a ) A current meter that has an internal resistance of 50 W is used to measure the current through resistor R B branch shown in the circuit of Figure Q1(a). (i) Draw the new circuit that showing the position of the ammeter. (2) (ii ) Determine the percentage of error of the reading and find the percentage of error of the reading if the voltage supply is change to 10 V. (4) (ii i) Give your comment on this situation. (1) (7 marks) ( b ) A voltmeter is used to measure the voltage across resistor R A in the circuit of Figure Q1(b). The sensitivity of the meter is 200 kW/V. (i) Draw the new circuit that showing the position of the voltmeter. (2) (ii ) Find the voltage reading across R A and the percentage of error of the reading if the range of voltmeter is 3 V. (4) (ii i) Give your comment on this situation. (1) (7 marks) ( c A 1 mA full-scale deflection current meter movement is to be used in an ohmmeter circuit of Figure Q1(c). The meter 7
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
BEE 2123
SOALAN DALAM BAHASA INGGERIS
Q1 (a) A current meter that has an internal resistance of 50 W is used to measure the current
through resistor RB branch shown in the circuit of Figure Q1(a).
(i) Draw the new circuit that showing the position of the ammeter. (2)
(ii) Determine the percentage of error of the reading and find the percentage of error
of the reading if the voltage supply is change to 10 V. (4)
(iii) Give your comment on this situation. (1)
(7 marks)
(b) A voltmeter is used to measure the voltage across resistor RA in the circuit of Figure
Q1(b). The sensitivity of the meter is 200 kW/V.
(i) Draw the new circuit that showing the position of the voltmeter. (2)
(ii) Find the voltage reading across RA and the percentage of error of the reading if
the range of voltmeter is 3 V. (4)
(iii) Give your comment on this situation. (1)
(7 marks)
(c) A 1 mA full-scale deflection current meter movement is to be used in an ohmmeter
circuit of Figure Q1(c). The meter movement has an internal resistance Rm of 100 W
and 5.0 V battery will be used in the circuit. Calculate,
(i) The value of standard resistance, RSTD. (1)
(ii) The value of RX that would cause 25%, 50%, 75% deflections and show the
position of pointer in the meter for every case. (3)
The ohmmeter is redesigned to make more efficient whereby one resistor R2 is
connected parallel with the PMMC and current meter is fixed to 0.5 mA of FSD.
(iii) Draw the new circuit of the ohmmeter. (1)
(iv) Calculate R2 when there is 15% drop in Eb and calculate Rx if the meter indicates
75% of FSD. (4)
(v) Explain the function of R2. (2)
(11 marks)
7
BEE 2123
Q2 (a) State two of most common methods to measure power in AC circuit and draw the
circuit of each method.
(3 marks)
(b) In one design of the AC ammeter, several factors need to be considered. The meter has