Exam 12: Transformers

Small transformers, such as those used for doorbell and signal circuits, are usually very efficient.

Transformers used for power distribution are wound on cores made of ____.

A(n) ____ is used for installations where heavy loads are used infrequently or where it is apparent that future demand may require additional loading.

When transformers are constructed, the windings are often placed on separate legs to minimize flux leakage.

What is one method of cooling a transformer?

The type of material from which the core is made affects the efficiency of the transformer.

If a transformer has a ratio of 10 to 1 (10:1), it is being used as a ____ transformer.

The coils of an air core transformer are wound on forms made of nonconducting materials.

One method of transformer construction is to build up thin, flat sections called ____.

The efficiency of a transformer may be as high as ____ percent.

If a transformer's primary winding has 200 turns and the secondary winding has 600 turns, the turns ratio is ____.

If a transformer increases the voltage, it is called a ____ transformer.

A transformer's audible hum is a result of the laminations and windings vibrating as the magnetic field alternates.

Air core transformers are ____.

The molecular motion caused by the magnetizing and demagnetizing of a transformer's core results in friction which produces heat. This heat loss plus the power loss caused by the magnetic lag is called the ____ loss.