Electrical measurements MCQ Quiz Hub

1. Range of an electrical instrument depends on ______
current
voltage
power
resistance

2. Moving coil instruments have a current and voltage rating of _______
100 A and 25 V
50 mA and 50 mV
75 nA and 100 μV
25 μA and 75 V

3. A shunt is a ______
very high resistance
medium resistance
very low resistance
high resistance

4. A shunt can be used to measure large currents.
True
False
all of the above
None of the mentioned

5. Current terminals have a small current capacity.
True
False
all of the above
None of the mentioned

6. Potential terminals have a ______
high current capacity
low voltage capacity
low current capacity
high voltage capacity

7. In case of AC ammeters, shunts consist of _______
impedance
capacitance
resistance
inductance

8. What is the effect of the ammeter range on the shunt resistance?
no effect
varies by a factor of multiplying factor
varies by a factor of the resistance
varies by a factor of unity

9. A multiplier is ______
non-inductive
resistive
capacitive
non-capacitive

10. What is the condition for using a multiplier in A.C. voltmeters?
by using ac supply
by maintaining a uniform impedance
by maintaining a uniform frequency
by using a galvanometer

11. What is the current transformer?
transformer used with an A.C. ammeter
transformer used with an D.C. ammeter
transformer used with an A.C. voltmeter
transformer used with an D.C. voltmeter

12. What is the potential transformer?
transformer used with an D.C. ammeter
transformer used with an A.C. voltmeter
transformer used with an D.C. ammeter
transformer used with an A.C. voltmeter

13. C.T. and P.T. are used for ____
measuring low current and voltages
measuring very low current and voltages
measuring high currentsand voltages
measuring intermediate currents and voltages

14. The primary winding of a C.T. has ____
a larger number of turns
no turns at all
intermediate number of turns
a few turns

15. The secondary winding of a C.T. has ______
a large number of turns
a few turns
no turns at all
intermediate number of turns

16. Turns ration for a C.T. is _______
n = Np ⁄ Ns
n = Ns ⁄ Np
n = 1 ⁄ Np
n = Ns

17. The primary winding of a P.T. has _____
intermediate number of turns
no turns at all
a larger number of turns
a few turns

18. The secondary winding of a P.T. has _______
a large number of turns
intermediate number of turns
no turns at all
a few turns

19. Instrument transformers can be easily replaced.
True
False
all of the above
None of the mentioned

20. Instrument transformers provide _____
electrical isolation from low rated winding
electrical isolation from high rated winding
electrical isolation from medium rated winding
no electrical isolation at all

21. Instrument transformers give same readings irrespective of number of other instruments connected.
True
False
all of the above
None of the mentioned

22. C.T. and P.T. are standardized at ____
50 A and 220 V
25 mA and 2.2 kV
5 A and 110 V
75 nA and 1.1 MV

23. A 5A ammeter can measure a current of upto 1000 A using a ______
5/1000A C.T.
1000A C.T.
5A C.T.
1000/5A C.T.

24. A 110V voltmeter can measure a voltage of upto 110kV using a ___
110000/110V P.T.
110000V P.T.
110V P.T.
110/110000V P.T.

25. How can the meter circuit be isolated from the power circuit?
by grounding
through electrical isolation
by physical separation
through mechanical isolation

26. How are instrument transformers different from shunts and multipliers?
they are all the same
they have transformers
readings are independent of component values
they can be used for high voltages and currents

27. Transformation ratio of an instrument is defined as _______
ratio of primary to secondary phasor
ratio of secondary to primary phasor
reciprocal of the primary phasor
reciprocal of the secondary phasor

28. Nominal ratio of an instrument transformer is defined as the _______
reciprocal of the rated primary value
ratio of rated secondary value to primary value
reciprocal of the rated secondary value
ratio of rated primary value to secondary value

29. Ratio correction factor is defined as ____
reciprocal of nominal ratio
ratio of nominal ratio to transformation ratio
ratio of transformation ratio to nominal ratio
reciprocal of transformation ratio

30. For a C.T. the turns ratio is defined as the ______
n = Np ⁄ Ns
n = 1 ⁄ Np
n = Ns
n = Ns ⁄ Np

31. For a P.T. the turns ratio is defined as the ______
n = Np ⁄ Ns
n = 1 ⁄ Np
n = Ns
n = Ns ⁄ Np

32. Errors are introduced in Current Transformers.
True
False
all of the above
None of the mentioned

33. Ratio error is defined as ______
Ratio error = Kn⁄R
Ratio error = Kn – R⁄R
Ratio error = Kn – R
Ratio error = 1⁄R

34. Ratio error is due to ____
iron loss
C.T.
magnetising component
supply voltage

35. Phase angle error is due to _____
C.T.
magnetising component
iron loss
supply voltage

36. In power measurements 180° phase shift is required.
True
False
all of the above
None of the mentioned

37. Errors in a C.T. can be minimised by _____
making use of laminations
having low reactance
increasing the secondary winding turns
decreasing the primary winding turns

38. The secondary leakage reactance of a C.T. ______
increases its ratio error
decreases its ratio error
has no effect on its ratio error
increases the impedance of the circuit

39. Secondary and primary windings consist of ______
copper turns
14 S.W.G copper wire and copper strip respectively
iron coils wound around
laminations

40. Coils of a C.T. are separately wound.
True
False
all of the above
None of the mentioned

41. The windings of a C.T. are _______
tied together
shorted
wound over one another
grounded

42. At high voltages, the current transformers are enclosed in a tank.
True
False
all of the above
None of the mentioned

43. Turns compensation is used to obtain ____
to compensate the turns
to equalise the turns on the windings
to protect the equipment
transformation ratio equal to nominal ratio

44. What is the effect of reducing the secondary turns in a C.T. by 1%?
transformation ratio reduces by the same value
no effect
nominal ratio increase by the same value
secondary current increases by the same value

45. In a 1000/5 A C.T., the number of secondary turns would be ________
200
199 or 198
5
1000

46. In the ring type of core, the secondary winding is ________
non-uniformly distributed over the core
shorted with the primary winding
uniformly distributed over the core
connected in the form of a ring

47. In a shell type of core, the windings are ________
in the form of the shell
shorted with the primary windings
not wound
placed on the central limb

48. Mumetal has _______
low permeability, high loss
high permeability, medium loss
medium permeability, high loss
high permeability, low loss

49. Perminder has ______
medium saturation point of permeability
low saturation point of permeability
no saturation point of permeability
high saturation point of permeability

50. In a C.T., the primary ampere turns is variable.
True
False
all of the above
None of the mentioned