Transformers

Question 1

Will a transfer work with a DC current?

Answer 1

No

Question 2

Explain your previous answer.

Answer 2

The purpose of a transformer is to raise or lower the value of an alternating voltage. It will not work with DC voltages as there is no change in the magnetic field.

Question 3

List 2 types of transformer construction.

Answer 3

Core type
Shell type

Question 4

What is the principle purpose of a transformer?

Answer 4

Trades voltage for current in a circuit, while not affecting the total electrical power.

Question 5

What is the purpose of the laminated soft iron core?

Answer 5

The windings are suitably insulated from the core and also from one another.

Question 6

If there are more coils in the secondary windings, what type of transformer is it and what will happen to the output voltage?

Answer 6

Step up transformer
More output voltage

Question 7

State the output voltage equation.

Answer 7

No of Secomdary Turns/ No of Primary Turns × input voltage

Question 8

What is the purpose of a centre tapped transformer?

Answer 8

Reduces the electric shock hazard caused by an earth on such equipment.

Question 9

Identify the input and output cables on HM Ships.

Answer 9

Input
Red-L1
Yellow-L2
Blue-L3
Output
Red-A
Yellow-B
Blue-C

Question 10

State the new, to be introduced, colour codes:

Answer 10

Input
Brown-L1
Black-L2
Grey-L3
Output
Brown-A
Black-B
Grey-C