# Instrument Transformers - MCQs with answers

## Instrument Transformers - MCQs with answers

Q1. 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: A. Ac ammeter and ac voltmeter respectively

Q2. 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: C. Both (a) and (b)

Q3. 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

Q4. 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

Q5. 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

Q6. 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. None of these

Q7. The nominal ratio for a current transformer is given by

A. rated primary winding current / rated secondary winding current

B. no. of turns in the primary winding / no. of turns in the secondary winding

C. no. of turns in the secondary winding / no. of turns in the primary winding

D. rated secondary winding current / rated primary winding current

ANSWER: A. rated primary winding current / rated secondary winding current

Q8. 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: A. Thick conductors and small length of turns

Q9. In potential transformer, with increase in frequency the phase angle

A. Increases
B. Decreases
C. Remains same
D. None of these

Q10. Under normal operating condition, the excitation current of current transformer and potential transformer

A. Both varies over a wide range
B. Varies over a wide range, remains constant
C. Remains constant, varies over a wide range
D. Both remains constant