Electrical and Electronics Measurement Mcq

1. Commonly used standard capacitor is

(a) concentric sphere type.
(b) parallel plate type.
(c) concentric cylinder type with guard ring.
(d) multiple parallel plate type.

2. Which one of the following meters is an integrating type instrument?

(a) Ammeter.
(b) Voltmeter.
(c) Wattmeter.
(d) Energy meter.

3. The …….. is an integrating type instrument:

(a) moving iron ammeter
(b) moving coil voltmeter.
(c) dynamometer wattmeter.
(d) induction type energy meter.

4. Industrial measuring instruments are of accuracy classes

(a) 0.5 and 1.
(b) 0.5, 1, 1.5, 2.5 and 5.
(c) 1, 1.5, 2.5 and 5.
(d) 1.0, 0.2 and 0.5.

5. The most suitable material for use as spring material for most of the applications, except in low resistance instruments, is

(a) platinum silver.
(b) phosphor-bronze.
(c) silicon bronze.
(d) hard-rolled silver.

6. Ideally, the damping torque should be

(a) proportional to the velocity of moving system and operating current.
(b) proportional to the velocity of the moving system but independent of operating current.
(c) independent of the velocity of the moving system and proportional to the operating current.
(d) independent of the velocity of the moving system and operating current.

7. To achieve the optimum transient response, the indicating instruments are so designed as to

(a) be critically damped.
(b) be undamped.
(c) providing damping which is slightly more than the critical value.
(d) providing damping which is slightly less than the critical value.

8. The damping torque must operate only when the moving system of the indicating instrument is

(a) actually moving.
(b) stationary.
(c) just starting to move.
(d) near its full deflection.

9. In eddy current damping systems, the disc employed should be of

(a) conducting and magnetic material.
(b) conducting but nonmagnetic material.
(c) magnetic but non-conducting material.
(d) non-conducting and nonmagnetic material.

10. For a sensitive galvanometer, the type of support used is

(a) suspension.
(b) taut suspension.
(c) unipivot suspension.
(d) none of these.

11. Preferred material for permanent magnet is

(a) stainless steel.
(b) alnico.
(c) tungsten steel.
(d) soft iron.

12. Due to which one of the following reasons bearings of PMMC instrument are made of Jewel ?

(a) To avoid wear and tear of the moving system.
(b) To provide a small support.
(c) It can be easily replaced.
(d) To make the system robust.

13. What is the ‘swamping’ resistance which is connected in series with the working coil of a voltmeter to drastically reduce the error in measurement caused due to variation in temperature; made of ?

(a) Constantan.
(b) Eureka.
(c) Manganin.
(d) Nichrome.

14. The galvanometer is protected during transport by

(a) connecting critical damping resistance across the galvanometer terminals.
(b) shorting the galvanometer terminals.
(c) keeping the galvanometer terminals open-circuited.
(d) a capacitor across the galvanometer terminals.

15. The response of a galvanometer is independent of its

(a) controlling torque.
(b) number of turns.
(c) circuit resistance.
(d) none of these.

16. The reflecting mirror mounted on the moving coil of a vibration galvanometer is replaced by a bigger size mirror. This will result in

(a) lower frequency of resonance and lower amplitude of vibration.
(b) lower frequency of resonance but the amplitude of vibration is unchanged.
(c) higher frequency of resonance and lower amplitude of vibration.
(d) higher frequency of response but the amplitude of vibration is unchanged.

17. In a ballistic galvanometer, the inertia of the moving system is large so that

(a) it is practically stationary during the period the electricity is passing through the coil.
(b) it is accelerating fast as soon as the coil is energized.
(c) the amplitude of oscillations is small.
(d) the frequency of oscillation is large.

18. Why is damping of a ballistic galvanometer kept small ?

(a) To get minimum overshoot.
(b) To make the system critically damped.
(c) To make the system ocsiliatory.
(d) To get first deflection large.

19. A PMMC instrument can be used as a flux meter by

(a) using a low resistance shunt.
(b) removing the control springs.
(c) making the control springs of large moment of inertia.
(d) using a high series resistance.

20. Flux meter is a special type of ballistic galvanometer provided with which one of the following ?

(a) Heavy electromagnetic damping and very small controlling torque.
(b) Heavy electromagnetic damping and large controlling torque.
(c) Small electromagnetic damping and controlling torque.
(d) Large controlling torque and small electromagnetic damping.