Transformer MCQs Part 20

Transformer MCQs Part 20

Which of following is major reason of occurrence of leakage flux in transformer

Which of following is major reason of occurrence of leakage flux in transformer:

1. Air is not a good magnetic insulator
2. The input voltage is sinusoidal in nature
3. Iron core has high permeability
4. None of these

Correct answer: 1. Air is not a good magnetic insulator

A transformer has maximum efficiency for which of following condition

A transformer has maximum efficiency for which of following condition:

1. When resistances of two windings are equal
2. When copper losses are equal to constant loss
3. When leakage reactances of two windings are equal
4. None of these

Correct answer: 2. When copper losses are equal to constant loss

The steel used for transformer core has

The steel used for transformer core has:

1. Low hysteresis losses
2. High permeability
3. High silicon content
4. All of these

Correct answer: 4. All of these

The transformer which should never have the secondary open-circuited when the primary is energized

The transformer which should never have the secondary open-circuited when the primary is energized:

1. Current transformer
2. Potential transformer
3. Power transformer
4. Autotransformer

Correct answer: 1. Current transformer

In an autotransformer, the power from primary is transferred to secondary

In an autotransformer, the power from primary is transferred to secondary:

1. Inductively
2. Conductively
3. Both inductively and conductively
4. None of these

Correct answer: 3. Both inductively and conductively