AC Electrics -Transformers: DGCA Technical General questions

Question 1

Instrument transformers normally:

Accepted Answer

Reduce the AC supply to 26 volts for some instruments

Answer

Convert 14 volts DC to 26 volts AC

Answer

Change 115 volts to 200 volts for engine instruments

Answer

Convert 28 volts DC to 28 volts AC

Question 2

An autotransformer:

Accepted Answer

Has only one coil which is used as both primary and secondary

Answer

Varies its turns ratio automatically to maintain a constant output voltage with varying input voltage

Answer

Will maintain a constant output frequency with a varying supply frequency

Answer

Requires an inductive supply

Question 3

A step up transformer is one in which the number of turns on the secondary winding is:

Accepted Answer

Greater than that on the primary

Answer

The same as the primary if the cable diameter is the same

Answer

Less than on the primary

Answer

Always the same as on the primary

Question 4

A transformer which halves the voltage will have:

Accepted Answer

Half as many turns on the secondary as on the primary

Answer

Twice as many turns on the secondary as on the primary

Answer

Half as much current flowing in the secondary as in the primary

Answer

Four times as many turns on the secondary as on the primary

Question 5

The power output of a transformer is:

Accepted Answer

The same as the power input

Answer

In proportion to the transformation ratio

Answer

In inverse proportion to the transformation ratio

Answer

Increased in a step up transformer

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