Physics B 2

Question 0

Describe the structure of a step up and a step down transformer and what each does

Answer 0

A step up transformer had more turns on the secondary coil than the primary coil it increases the voltage to make it travel faster along pylons

A step down transformer has more turns on the primary coil than the secondary coil it is used to step down the voltage to a level more suitable for household use

They both have an iron core

Question 1

What do transformers do in terms of electricity

Answer 1

They change the potential difference but only the AC potential difference

Question 2

What does an iron core carry?

Answer 2

They carry a magnetic field not a current

Question 3

What is the transformer equation?

Answer 3

P.d across primary coil=number of turns prim coil
———————— —————————–
P.d across sec coil Number of turns sec coil

Question 4

What is the formula for power supplied

Answer 4

Power = current x potential difference

Question 5

What is a switch mode transforme

Answer 5

They are a type of transformer that operate at higher frequencies than traditional transformers usually at between 50khz 200khz.

Because they work at higher frequencies they are much lighter and smaller

The use very little power when there is no load