MCQ: Which of the following insulating materials can withstand the highest temperature safely ?

1. Cellulose
2. Asbestos
3. Mica
4. Glass fibre

MCQ: Which of the following does not change in a transformer ?

1. Current
2. Voltage
3. Frequency
4. All of the above

MCQ: In a transformer the energy is conveyed from primary to secondary_________?

1. through cooling coil
2. through air
3. by the flux
4. none of the above

MCQ: A transformer core is laminated to__________?

1. reduce hysteresis loss
2. reduce eddy current losses
3. reduce copper losses
4. reduce all above losses

MCQ: The degree of mechanical vibrations produced by the laminations of a transformer depends on____________?

1. tightness of clamping
2. gauge of laminations
3. size of laminations
4. all of the above

MCQ: The no-load current drawn by transformer is usually what per cent of the full-load current ?

1. 0.2 to 0.5 per cent
2. 2 to 5 per cent
3. 12 to 15 per cent
4. 20 to 30 per cent