Transformers

A step-up transformer has more turns on the primary coil than the secondary coil.

• True

• False

Transformers only work with ___________ current.

• alternating

• direct

The core of a transformer is made of iron because...

• it is strong

• it conducts electricity

• it is a soft magnetic material

• it is a hard magnetic material

• it has a high melting point

In a transformer, the input power is __________ the output power.

• less than

• equal to

• greater than

A transformer has 15 turns on its primary coil and 30 turns on its secondary coil. This is a....

• step-up transformer

• step-down transformer

A step-up transformer has an input power of 75 W. What is the output power?

(a)  

A step-down transformer has an input voltage of 50 V. The output voltage will be...

• less than 50 V

• 50 V

• greater than 50 V

A step-down transformer has an input current of 50 A. The output voltage will be...

• less than 50 A

• 50 A

• greater than 50 A

A step-up transformer is supplied with 100 V from a DC supply. What will the output voltage be?

(a)  

The ratio of potential difference across the primary coil to the potential difference across the secondary coil of a transformer is 2:1. The primary coil has 20 turns. How many does the secondary coil have?

(a)