electrical

Electrical Instruments MCQ Objective Questions and Answers Page - 2

1.

In a 3-phase power measurement by two wattmeter method, both the wattmeters had identical readings. The power factor of the load was

Answer/ Hint      

Answer : A

Explanation :

2.

In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The power factor of the load must be

Answer/ Hint      

Answer : B

Explanation :

3.

The adjustment of position of shading bands, in an energy meter is done to provide

Answer/ Hint      

Answer : A

Explanation :

4.

An ohmmeter is a

Answer/ Hint      

Answer : B

Explanation :

5.

For measuring a very high resistance we should use

Answer/ Hint      

Answer : C

Explanation :

6.

The electrical power to a megger is provided by

Answer/ Hint      

Answer : B

Explanation :

7.

In a megger controlling torque is provided by

Answer/ Hint      

Answer : C

Explanation :

8.

The operating voltage of a megger is about

Answer/ Hint      

Answer : D

Explanation :

9.

Murray loop test can be used for location of

Answer/ Hint      

Answer : C

Explanation :

10.

Which of the following devices should be used for accurate measurement of low DC voltage?

Answer/ Hint      

Answer : B

Explanation :

11.

It is required to measure the true open circuit emf of a battery. The best device is

Answer/ Hint      

Answer : C

Explanation :

12.

A voltage of about  200 V  can be measured

Answer/ Hint      

Answer : B

Explanation :

13.

A direct current can be measured by

Answer/ Hint      

Answer : B

Explanation :

14.

To measure a resistance with the help of a potentiometer it is

Answer/ Hint      

Answer : B

Explanation :

15.

A phase shifting transformer is used in conjunction with

Answer/ Hint      

Answer : B

Explanation :

16.

Basically a potentiometer is a device for

Answer/ Hint      

Answer : A

Explanation :

17.

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

Answer/ Hint      

Answer : A

Explanation :

18.

The stator of phase shifting transformer for use in conjunction with an AC potentiometer usually has a

Answer/ Hint      

Answer : B

Explanation :

19.

In an AC co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be

Answer/ Hint      

Answer : A

Explanation :

20.

For measurements on high voltage capacitors, the suitable bridge is

Answer/ Hint      

Answer : C

Explanation :

21.

In an Anderson bridge, the unknown conductance is measured in terms of

Answer/ Hint      

Answer : B

Explanation :

22.

Wagner earthing device is used to eliminate errors due to

Answer/ Hint      

Answer : A

Explanation :

23.

For measurement of mutual inductance we can use

Answer/ Hint      

Answer : C

Explanation :

24.

For measurement of inductance having high value, we should use

Answer/ Hint      

Answer : C

Explanation :

25.

If the current in a capacitor leads the voltage by  800, the loss angle of the capacitor is

Answer/ Hint      

Answer : A

Explanation :

26.

In a Schering bridge the potential of the detector above earth potential is

Answer/ Hint      

Answer : A

Explanation :

27.

To avoid the effect of stray magnetic field in AC bridges we can use

Answer/ Hint      

Answer : A

Explanation :

28.

If an inductance is connected in one arm of bridge and resistances in the remaining three arms

Answer/ Hint      

Answer : B

Explanation :

29.

A power factor meter has

Answer/ Hint      

Answer : A

Explanation :

30.

The two pressure coils of a single phase power factor meter have

Answer/ Hint      

Answer : A

Explanation :

31.

In a single phase power factor meter the phase difference between the currents in the two pressure coils is

Answer/ Hint      

Answer : C

Explanation :

32.

In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at

Answer/ Hint      

Answer : D

Explanation :

33.

In a vibrating reed frequency meter the natural frequencies of two adjacent reeds have a difference of

Answer/ Hint      

Answer : C

Explanation :

34.

On a Weston frequency meter, the magnetic axes of the two fixed coils are

Answer/ Hint      

Answer : B

Explanation :

35.

A Weston frequency meter is

Answer/ Hint      

Answer : B

Explanation :

36.

A Weston synchronoscope is a

Answer/ Hint      

Answer : C

Explanation :

37.

In a Weston synchronoscope, the fixed coils are connected across

Answer/ Hint      

Answer : B

Explanation :

38.

In Weston synchronoscope, the moving coil is connected across

Answer/ Hint      

Answer : A

Explanation :

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