magnetism

Question 1

magnetic field=

Answer 1

the area around a magnet where a force exists

Question 2

magnetism is a _____ force

Answer 2

non contact

Question 3

magnetic materials are _____ by magnets

Answer 3

attracted

Question 4

how to unmagnetise a material (2)

Answer 4

use heat, pass thermal energy through it

touch it with a non-magnetic material

Question 5

what are the ways to make an electromagnet stronger?

Answer 5

1. more turns on the coil
2. more electrical current
3. use an iron core

Question 6

relay purpose, function

Answer 6

allows one circuit to control another

it switches on motors and is used as a circuit breaker

Question 7

what does a split ring commutator do

Answer 7

it constantly reverses the current, ensuring constant 360° rotation

Question 8

domain theory

Answer 8

inside a magnetic material there are many mini magnets called domains

when they are lined up so that they face the same way, a permanent magnet is formed

Question 9

how can iron filings be used to reveal the magnetic field of a bar magnet

Answer 9

they stick to the magnet and reveal the shape of the magnetic field because more will attract to stronger areas