Electromagnets

Question 1

Can electromagnets be turned on and off?

Answer 1

Yes

Question 2

How many elements are magnetic?

Answer 2

3, nickel, iron and cobalt. (Also steel, which is an alloy)

Question 3

Why is a bar magnet a permanent magnet?

Answer 3

Because it cannot be turned on and off. (It is always magnetic)

Question 4

How can you show if a magnet is a magnet?

Answer 4

By showing that it repels, because magnetic materials that aren’t magnets can only attract.

Question 5

Where is the magnetic field strongest?

Answer 5

At the poles. They are also more concentrated. Field lines go N to S. Field lines have arrows.

Question 6

What are the units of power?

Answer 6

Watts

Question 7

When an electric current flows in a wire, what does it create?

Answer 7

A magnetic field.

Question 8

How can an electromagnet be strengthened?

Answer 8

1) By wrapping the coils around an iron core
2) By adding more coils
3) Increasing the current flowing through the coil