# Transformer MCQs Part 1

Transformer MCQs Part 1.

## The value of flux involved in the EMF equation of a transformer is

The value of flux involved in the EMF equation of a transformer is

1. Average value
2. Maximum value
3. Rms value
4. Instantaneous value

Correct answer: 2. Maximum value

## No-load current in a transformer

No-load current in a transformer

1. Lags behind the voltage by about 15°
2. Leads the voltage by about 15°
3. Lags behind the voltage by about 75°
4. Leads the voltage by about 75°

Correct answer: 3. Lags behind the voltage by about 75°

## The Buchholz relay can be installed on

The Buchholz relay can be installed on

1. Auto-transformers
2. Welding transformers
3. Oil cooled transformers
4. Air-cooled transformers

Correct answer: 3. Oil cooled transformers

## Natural air cooling is usually restricted for transformers up to

Natural air cooling is usually restricted for transformers up to

1. 1.5 MVA
2. 5 MVA
3. 15 MVA
4. 50 MVA

Correct answer: 1. 1.5 MVA

## The no-load current drawn by the transformer is typically what percent of the full-load current

The no-load current drawn by the transformer is typically what percent of the full-load current

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

Correct answer: 2. 2 to 5 %