1. Positive regulation of the transformer is indication of ___ load
a) Inductive
b) Capacitive
c) Either inductive or capacitive
d) Resistive
2. A transformer is supplying pure resistive (unity power factor) load. The power factor of the transformer will be:
a) about 0.95 (lead)
b) about 0.95 (lag)
c) unity
d) 0.8
3. During short circuit the core losses are negligible because:
a) The voltage applied across the high voltage side is fraction of the rated volage
b) The current on the low voltage side is very small
c) the power factor is almost zero
d) Iron becomes saturated
4. The open circuit test of the transformer gives information related to:
a) magnetizing current
b) core loss
c) both magnetizing current and core loss
d) None of the above
5. If the thickness of the laminations used in the transformer core are increased. Then which losses will increase:
a) eddy current
b) hysteresis
c) copper loss
d) both a and b
6. The losses which vary with variation in the load are:
a) Hysteresis loss
b) copper losses
c) eddy current losses
d) All the above
7. The desirable properties of transformer core are:
a) Low permeability and low hysteresis loss
b) High permeability and low hysteresis loss
c) Low permeability and high hysteresis loss
d) High permeability and high hysteresis loss
8.The all day efficiency of the transformer is applicable to:
a) Power transformer
b) Distribution transformer
c) Auto transformer
d) Only (a) and (b)
a) Inductive
b) Capacitive
c) Either inductive or capacitive
d) Resistive
2. A transformer is supplying pure resistive (unity power factor) load. The power factor of the transformer will be:
a) about 0.95 (lead)
b) about 0.95 (lag)
c) unity
d) 0.8
3. During short circuit the core losses are negligible because:
a) The voltage applied across the high voltage side is fraction of the rated volage
b) The current on the low voltage side is very small
c) the power factor is almost zero
d) Iron becomes saturated
4. The open circuit test of the transformer gives information related to:
a) magnetizing current
b) core loss
c) both magnetizing current and core loss
d) None of the above
5. If the thickness of the laminations used in the transformer core are increased. Then which losses will increase:
a) eddy current
b) hysteresis
c) copper loss
d) both a and b
6. The losses which vary with variation in the load are:
a) Hysteresis loss
b) copper losses
c) eddy current losses
d) All the above
7. The desirable properties of transformer core are:
a) Low permeability and low hysteresis loss
b) High permeability and low hysteresis loss
c) Low permeability and high hysteresis loss
d) High permeability and high hysteresis loss
8.The all day efficiency of the transformer is applicable to:
a) Power transformer
b) Distribution transformer
c) Auto transformer
d) Only (a) and (b)
