# Measurement of Resistance - 2 - MCQs with answers

## Measurement of Resistance - 2 - MCQs with answers

Q1. The sensitivity of the bridge is maximum when

A. P/R = Q/S = 0

B. P/R = 1

Q2. During a test, the strain gauge with resistance of 200 ohm undergoes a change of 0.120 ohm and the strain of the gauge is 1.2 X10-4. Then the gauge factor will be

A. 4
B. 5
C. 4.5
D. 6

Q3. Wheatstone bridge is suitable for the measurement of

A. Low resistance
B. Medium resistance
C. High resistance
D. Very high resistance

Q4. The resistances of the various arms of Wheatstone bridge are P = 500 ohm, Q = 50 ohm, R = 1010 ohm and S = 100 ohm. The emf of the batter is 5 V and the current sensitivity of galvanometer is 8 mm/μA. If the internal resistance of the galvanometer is 80 ohm then the deflection of galvanometer and the sensitivity of the bridge in terms of deflection per unit change of resistance are

A. 151.2 mm, 30.24 mm/ohm
B. 100 mm, 21.03 mm/ohm
C. 186 mm, 40.37 mm/ohm
D. 193 mm, 20.74 mm/ohm

ANSWER: A. 151.2 mm, 30.24 mm/ohm

Q5. To produce a change of 2 mm in deflection of galvanometer, a change of 4 ohm is required in the unknown arm of a Wheatstone bridge. The sensitivity of the galvanometer is

A. 1 mm/ohm
B. 0.5 mm/ohm
C. 1.5 mm/ohm
D. 2 mm/ohm

Q6. In a Wheatstone bridge, if P = 10 ± 1%, Q = 100 ± 1%, R = 20 ± 1% and S is unknown then the unknown resistance will be

A. 200 ± 1%
B. 200 ± 2%
C. 200 ± 3%
D. 100 ± 1%

Q7. A highly sensitive galvanometer is used in Wheatstone bridge and it can detect a current as low as 80 pA. The resistances of each arm of bridge are 800 ohm and the resistance of galvanometer is 40 ohm. If an input of 20 V is applied to the bridge then the smallest change in resistance which can be detected is

A. 10.752 μA
B. 15.280 μA
C. 17.351 μA
D. 23.719 μA

Q8. The method/methods suitable for the measurement of low resistance is/are

A. Ammeter-voltmeter method
B. Kelvin’s double bridge method
C. Potentiometer method
D. All of these