# Open & Short Circuit Tests in Single-Phase Transformer - MCQs with Answers

## Open & Short Circuit Tests in Single-Phase Transformer - MCQs with Answers

Q1. While performing a circuit test on transformer at 30v, 30 Hz it gives Φ1 as lagging power factor. If the same test is performed at 30V, 50Hz, then

a. Φ1 > Φ2
b. Φ1 < Φ2
c. Φ1 = Φ2
d. None of these

Q2. If the magnitude of leakage reactance is equal to the resistance of both primary and secondary of a single phase transformer. Then the input power factor is

a. 1 / √2
b. 1
c. √2
d. zero

Q3. Open circuit test is to be performed on transformer to find

a. Constant losses
b. Copper losses
c. Both constant losses and copper losses
d. None of these

Q4. If the transformer is step-up transformer then for performing short circuit test meter is connected to the

a. H.V. side
c. L.V. side
c. Any side
d. Test cannot be performed on step up t / f

Q5. If short circuit test is performed on the transformer with constant rated voltage and increased frequency, then the short circuit current and power factor

a. Both will increase
b. Both will decrease
c. Increase, decrease
d. Decrease, remains constant