This set of Electrical Measurements Objective Questions & Answers focuses on “Advanced Problems on Measurement of Low Medium and High Resistance”.

1. Circuit shows the method of Measurement of low resistance by Ammeter-Voltmeter method. The measured resistance Rm for the given Circuit is _________

a) R_{x} + R_{v}

b) R2xRx+Rv

c) R2vRx+Rv

d) RxRvRx+Rv

2. Circuit shows the method of Measurement of low resistance by Ammeter-Voltmeter method. What is the percentage error?

a) Zero

b) RxRx+Rv × 100

c) –RxRx+Rv × 100

d) –RvRx+Rv × 100

3. The readings of polar type potentiometer are I = 12.4∠27.5°, V = 31.5∠38.4°. Then, reactance of the coil will be ________

a) 2.51 Ω

b) 2.56 Ω

c) 2.54 Ω

d) 2.59 Ω

4. The voltage drop across a standard resistor of 0.2 Ω is balanced at 83 cm. Find the magnitude of the current, if the standard cell emf of 1.53 V is balanced at 42 m.

a) 13.04 A

b) 10 A

c) 14.95 A

d) 12.56 A

5. A resistance R is measured using the connection shown in the below figure.

The current measured is 10 A on ranges 100A and the voltage measured is 125 V on 150 V range. The scales of the ammeter and voltmeter are uniform. The total number of scale divisions of the ammeter is 100 and that of the voltmeter is 150. The scale division can be distinguished. The constructional error of the ammeter is ± 0.3% and that of voltmeter±0.4%. The resistance of the ammeter is 0.25 Ω.

The value of R is?

a) 12.75 Ω

b) 12.0 Ω

c) 12.25 Ω

d) 12.5 Ω

6. A resistance R is measured using the connection shown in the below figure.

The current measured is 10 A on ranges 100A and the voltage measured is 125 V on 150 V range. The scales of the ammeter and voltmeter are uniform. The total number of scale divisions of the ammeter is 100 and that of the voltmeter is 150. The scale division can be distinguished. The constructional error of the ammeter is ± 0.3% and that of voltmeter±0.4%. The resistance of the ammeter is 0.25 Ω.

The possible error in the measurement of R is?

a) ±0.11 Ω

b) ±0.15 Ω

c) ±0.867 Ω

d) ±0.625 Ω

7. Low resistance is measured by ___________

a) De-Sauty’s bridge

b) Maxwell’s bridge

c) Kelvin double bridge

d) Wein’s bridge

8. The resistance can be measured most accurately by _________

a) Voltmeter-Ammeter method

b) Bridge method

c) Multimeter

d) Megger

9. A slide wire potentiometer has 10 wires of 2 m each. With the help of a standard voltage source of 1.045 V, it is standardized by keeping the jockey at 104.5 cm. If the resistance of potentiometer wires is 2000 Ω, then the value of working current is?

a) 1 mA

b) 10 mA

c) 0.1 mA

d) 0.5 mA

10. Which of the following method is used for the measurement of Medium Resistance?

a) Kelvin’s double bridge method

b) Carey-Foster bridge method

c) Anderson Bridge

d) Direct-Deflection method

11. In the Wheatstone bridge shown below, if the resistance in each arm is increased by 0.05%, then the value of Vout will be ________

a) 50 mV

b) Zero

c) 5mV

d) 0.1mV