Transformer MCQs Part 40

Electrical Engineering MCQ on Transformer

Auto-transformer makes effective saving on copper and copper losses if its transformation ratio is

Auto-transformer makes effective saving on copper and copper losses if its transformation ratio is

1. Approximately equal to one
2. Great than one
3. Less than one
4. None of above

Correct answer: 1. Approximately equal to one

The no-load current drawn by transformer is generally what percentage of the full-load current

The no-load current drawn by transformer is generally what percentage of the full-load current

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

Correct answer: 3. 2 to 5 per cent

The secondary of a current transformer is always short-circuited under operating conditions since it

The secondary of a current transformer is always short-circuited under operating conditions since it

1. Avoids core saturation and high voltage induction
2. Is safe to human beings
3. Protects the primary circuit
4. None of above

Correct answer: 1. Avoids core saturation and high voltage induction

The no load current in a transformer lags behind the applied voltage by an angle of what degrees

The no load current in a transformer lags behind the applied voltage by an angle of what degrees

1. 120°
2. 180°
3. 75°
4. 90°

Correct answer: 3. 75°

The maximum efficiency of a distribution transformer is designed to occur

The maximum efficiency of a distribution transformer is designed to occur

1. At 50% full load
2. At 80% full load
3. At full load
4. At no load

Correct answer: 1. At 50% full load