Topic 10- Magnetism And The Motor Effect

Question 1

Induced magnet

Answer 1

When a piece of magnetic material becomes a magnet when it’s in a magnetic field. It stops being a magnet when it’s taken out of the magnetic field.

Question 2

What is earths magnetic field caused by

Answer 2

Electric currents in the molten outer core which is made from a mix of iron and nickel.

Question 3

What do we use to draw the shape of the magnetic field around a wire carrying current or around a magnet and why is this?

Answer 3

A plotting compass
You use this to find the direction of the magnetic field. The direction of the magnetic field depends on the direction of the current. If the current changes direction, so does the direction of the magnetic field (and therefore plotting compasses)

Question 4

In what direction does the needle of a plotting compass point?

Answer 4

In the direction of earths North Pole

Question 5

What’s a uniform magnetic field

Answer 5

Where two flat magnets produce a magnetic field with the same direction and strength everywhere.

Question 6

What’s an electromagnet

Answer 6

A coil of wire with current flowing through it

Question 7

How to make the magnetic field of an electromagnet stronger

Answer 7

Put a piece of iron (an iron core) inside the coil. This becomes a temporary magnet- it’s only magnetic while the magnetic field from the electromagnet is affecting it