Measurement and Instrumentation Multiple Choice Questions and Answers

31. In order to achieve high accuracy, the slide wire of a potentiometer should be

1. as long as possible
2. as short as possible
3. neither too small not too large
4. very thick

32. In Weston synchronoscope the moving coil is connected across

1. bus-bars
2. incoming alternator
3. fixed coils
4. any of the above

33. Induction type single phase energy meters measure electric energy in

1. kW
2. Wh
3. kWh
4. VAR

34. Instrument transformers are

1. potential transformers
2. current transformers
3. both a and b
4. power transformers

35. is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another

1. Tangent galvanometer
2. Meggar
3. Current transformer
4. None of the above

36. It is required to measure the true open circuit e.m.f. of a battery. The best device is

1. D.C. voltmeter
2. Ammeter and a known resistance
3. D.C. potentiometer
4. None of the above

37. Most common form of A.C. meters met with in every day domestic and industrial installations are

1. mercury motor meters
2. commutator motor meters
3. induction type single phase energy meters
4. all of the above

38. Most sensitive galvanometer is

1. elastic galvanometer
2. vibration galvanometer
3. Duddlb galvanometer
4. spot ballistic galvanometer

39. Murray loop test can be used for location of

1. ground fault on a cable
2. short circuit fault on a cable
3. both the ground fault and the short-circuit fault
4. none of the above

40. Operating torques in analogue instruments are

1. deflecting and control
2. deflecting and damping
3. deflecting, control and damping
4. vibration and balancing