# Losses in Single-Phase Transformer - MCQs with Answers

## Losses in Single-Phase Transformer - MCQs with Answers

Q1. If the voltage supply of a single phase transformer is doubled and the supply frequency is halved, then the eddy current loss will become

a. remains same
b. double of the original
c. four times of original
d. half of the original

ANSWER: c. four times of original

Q2. For a single phase no load transformer, which among the following losses will be minimum ?

a. hysteresis losses
b. eddy current losses
c. copper losses
d. mechanical losses

Q3. In the design of transformer, higher flux density is used. Due to which

a. weight per kVA increases
b. weight per kW increases
c. weight per kW decreases
d. weight per kVA decreases

ANSWER: d. weight per kVA decreases

Q4. If the applied voltage is increased by 10% and the applied frequency is increased by 20% of a single phase transformer, the percentage change in eddy current losses will be

a. 19%
b. 20%
c. 21%
d. 40%

Q5. A 600kVA transformer has core losses of 1w at 25 Hz and 2.5w at 50 Hz (neglecting resistances and assuming flux density to be constant). The power required at 60 Hz is

a. 3 watt
b. 3.5 watt
c. 3.24 watt
d. 3.54 watt

Q6. What happens to the hysteresis losses and eddy current losses, if the frequency of a transformer is increased keeping the supply voltage constant?

a. Both will decrease
b. Hysteresis losses will increase and eddy current losses will decrease
c. Hysteresis losses will remain same and eddy current losses will decrease
d. Hysteresis losses will decrease and eddy current losses will remain same