Magnets/ Magnetic Fields and Electromagnets

Question 1

What is a magnetic field

Answer 1

• A force around a magnet
• The force of attraction is always north to south
• the closer the lines, the stronger the force is

Question 2

The magnetic compass in relation to the geographical north and south
+ the earths magnet

Answer 2

• the north of the compass points to the geographical north of the Earth
• the geographical north is the south of the Earth’s magnet as opposites attract
• magnetic field lines will align the north of the compass and direct it to the south magnet

Question 3

Electromagnet

Answer 3

-temporary magnet produced using an electric current

Question 4

Core

Answer 4

• a rod of a magnetic material placed inside a coil to make the magnetic field stronger

Question 5

Magnetise

Answer 5

Make into a magnet

Question 6

Different cores

Answer 6

• iron cores can lose magnetic easily = they are weaker cores but are good for switching off magnetism quickly
• steel cores are very strong and keep magnetism =means you can’t easily turn off

Question 7

Magnetic field on a wire

Answer 7

• when current is flowing through a wire

- a magnetic field forms circles around it

Question 8

Coil of wire and magnetic field

Answer 8

• when a current flows through a could of wire

- magnetic fields will look similar to that of a bar magnet =lines from north to south

Question 9

Increase the strength of an electromagnet

Answer 9

• increase number of turns of coil
• add a core
• increase current flowing through the wire

Question 10

Uses of an electromagnet

Answer 10

• picking something up the dropping it somewhere

- e.g moving a Brocken car to the junkyard