Deck 8: Transformers

Question 1

If there are more turns of wire on the primary winding than on the secondary winding, the output voltage will be ____________________ than the input voltage

Answer 1

lower

Question 2

What are two basic types of transformers?

Answer 2

Two basic types of transformers are the insulating transformer and the autotransformer.

Question 3

A major disadvantage of the autotransformer over the insulating type is its lighter weight and compact size.

Answer 3

False

Question 4

Most insulating transformer installations are not separately derived systems.

Question 5

When there are several different secondary windings supplying the secondary conductors, an overload could occur on one or more secondary conductors and go undetected by the primary overcurrent protection.

Question 6

A transformer is permitted to be protected by one overcurrent device on the primary side rated not more than ____________________% times the primary full-load current.

Question 7

Transformers, except for small sizes, are often supplied with ___________________ to compensate for abnormally low or high primary voltage.

Question 8

A transformer has 30 turns on the primary winding and 10 turns on the secondary winding.Calculate the turns ratio for this transformer.

Question 9

Transformers are of the dry type or oil filled.

Question 10

What is the purpose of a transformer?

Question 11

Generally, a maximum of ____________________% of the electrical energy is lost in a transformer.

Question 12

The overcurrent device protecting the primary of a transformer is permitted to be rated as large as___________________% times the primary full-load current, provided the transformer secondary winding is protected.

Question 13

What is a zig-zag transformer?

Question 14

The overcurrent protection rules for a transformer do not provide for the protection of the conductors supplying a transformer or the conductors leading away from the transformer.

Question 15

Briefly discuss the new requirement regarding the disconnecting means of transformers.

Question 16

A 3-phase transformer is connected for a 300-volt primary and a 100-volt secondary.The transformer has a rating of 3 kVA.Determine the primary winding and the secondary winding full-load current of the transformer.

Question 17

The ___________________ transformer is used to make small adjustments in voltage, either up or down.

Question 18

Article ____________________ deals with transformers and transformer vaults.

Question 19

What happens when dual-voltage transformers are connected improperly?

Question 20

The output winding to a transformer is called the ____________________winding.