Instrument transformers - Electrical Engineering (MCQ) questions and answers

1)   The nominal ratio for a current transformer is given by

a. (rated primary winding current)/(rated secondary winding current)
b. (number of turns in the primary winding)/(number of turns in the secondary winding )
c. (number of turns in the secondary winding)/(number of turns in the primary winding )
d. (rated secondary winding current)/(rated primary winding current)
Answer  Explanation 

ANSWER: (rated primary winding current)/(rated secondary winding current)

Explanation:
No explanation is available for this question!


2)   Current transformers and potential transformers are used to increase the ranges of

a. AC ammeter and AC voltmeter respectively
b. AC ammeter and DC voltmeter respectively
c. DC ammeter and DC voltmeter respectively
d. DC ammeter and AC voltmeter respectively
Answer  Explanation 

ANSWER: AC ammeter and AC voltmeter respectively

Explanation:
No explanation is available for this question!


3)   The resistances of potential transformer winding is minimized by using

a. Thick conductors and small length of turns
b. Thin conductors and small length of turns
c. Thin conductors and large length of turns
d. Thick conductors and large length of turns
Answer  Explanation 

ANSWER: Thick conductors and small length of turns

Explanation:
No explanation is available for this question!


4)   If an instrument transformer is used to extend the ranges of AC instrument, then its reading will depend on

a. R
b. L
c. C
d. All of these
e. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


5)   The potential transformers are used to measure large voltage using

a. High range voltmeter
b. Low range voltmeter
c. High range ammeter
d. Low range ammeter
Answer  Explanation 

ANSWER: Low range voltmeter

Explanation:
No explanation is available for this question!


6)   Primary current in a current transformer is determined by

a. The load on the system
b. The load on its own secondary
c. The load on its own primary
d. All of these
Answer  Explanation 

ANSWER: The load on the system

Explanation:
No explanation is available for this question!


7)   The transformer ratio of the transformer depends upon the

a. Exciting current
b. Secondary current
c. Power factor of secondary circuit
d. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


8)   For the measurement of energy and power it is essential to know

a. Only the transformation ratio
b. Phase angle between the primary and secondary currents
c. Both (a) and (b)
d. None of these
Answer  Explanation 

ANSWER: Both (a) and (b)

Explanation:
No explanation is available for this question!