Magnetism and electromagnets

Question 1

What do magnets do?

Answer 1

Repel and attract other magnets and attract other magnetic substances

Question 2

What does a magnetically hard material do?

Answer 2

It keeps its magnetism after it has been magnetised

Question 3

When is magnetism induced in some materials?

Answer 3

When they’re placed in magnetic fields

Question 4

How do you show the magnetic field pattern of a bar magnet?

Answer 4

1. Place a bar magnet between two books and a sheet of paper on it
2. Sprinkle some iron filling on the paper above the magnet
3. Gently tap the paper
4. The iron fillings will move to show the magnetic field pattern
   OR
5. Place a bar magnet on a piece of paper
6. Place a number on small compasses on the paper near the magnet
7. Look carefully at the pattern shown by the needles to the compasses

Question 5

What does electrical current in a conductor do?

Answer 5

Creates a magnetic field around it

Question 6

What is often referred to as an electromagnet?

Answer 6

A soft iron core and a solenoid

Question 7

Right hand grip rule (for fields)

Answer 7

When the thumb of your right hand is pointing in the direction of the current, your fingers point in the direction of the field

Question 8

Right hand grip rule (for poles)

Answer 8

When the fingers of your right hand are pointing in the direction of the current, your thumb points to the North Pole of the solenoid