Transformer

Question 1

What is the job of a transformer?

Answer 1

To change the potential difference of a power supply

Question 2

What does a step-up transformer do?

Answer 2

Increases voltage and decreases current

Question 3

What does a step-down transformer do?

Answer 3

Decreases voltage and increases current

Question 4

Describe the structure of a transformer

Answer 4

Made of two coils of wire wound round an iron core

Question 5

What is the equation for electrical power?

Answer 5

Electrical power = current x potential difference

Question 6

What is electromagnetic induction in a transformer?

Answer 6

The voltage in one coil (of the transformer) causes/induces a voltage in the second coil

Question 7

Which is the only type of current that will work with transformers?

Answer 7

Alternating current

Question 8

Write an equation to show that if a transformer
is 100% efficient then the power in the
secondary coil = power in the primary coil

Answer 8

Vp x Ip = Vs x Is

Question 9

What is the national grid?

Answer 9

A network of wires/cables to distribute

power around the country.

Question 10

The primary core of a transformer is connected to a
solar cell. It has a potential difference 200 v across
its coil, which as 20 turns. The secondary coil has 30
turns. Explain the output voltage across the
secondary core

Answer 10

0 V
A solar cell is a d.c. source
(transformers only work with ac)