Magnetism

Question 1

A magnet can be used to sort aluminium
cans from steel cans. Explain how this
works

Answer 1

The magnet will attract the steel cans only (1)
because steel is a magnetic material
(aluminium is not magnetic)

Question 2

What is an induced magnet

Answer 2

When a magnetic material is placed in a

magnetic field and becomes a magnet itself

Question 3

What is a uniform magnetic field?

Answer 3

Has the same strength (1)
and direction (everywhere)

Question 4

State what is meant by a solenoid

Answer 4

A coil of wire (1)

with a current flowing through it

Question 5

Explain where the magnetic field is

strongest in a solenoid

Answer 5

Inside the coil (1)
because the fields (from individual coils)
reinforce each other

Question 6

What is the advantage of an
electromagnet versus a permanent
magnet

Answer 6

The electromagnet can be switched on or off

Question 7

In the right hand rule, what do the fingers

and thumb represent?

Answer 7

Fingers = the direction (of the magnetic field)
(1)
Thumb = the direction of current

Question 8

Describe two ways in which the magnetic

field around a wire can be changed (

Answer 8

Increase current(increases strength) (1)
Change the direction of current (changes the
magnetic field direction)

Question 9

Higher: What is the motor effect?

Answer 9

A force experienced by a wire carrying a

current in a magnetic field

Question 10

Higher: In Flemings left hand rule what do

the thumb, index and middle finger show?

Answer 10

Thumb = direction of force (1)
Index = direction of magnetic field (1)
Middle = Direction of current