Electromagnetism

Which electromagnet is stronger?

• A

• B

This is a picture of a simple electromagnet. How can the electromagnet be made stronger?

• Add more coils of wire to the nail.
• Use a smaller battery.
• Reverse the poles of the magnet.
• Remove all the coils and the nail.

In order for an electromagnet to be formed, an __________ current must pass through a coil of __________ wrapped around an ________ core.

• wire, iron, electric
• electric, wire, iron
• iron, electric, wire
• excited, hair, apple

Which of these bests describes an electromagnet?

• A permanent magnet made from electric currents.

• A temporary magnet made from electric currents.

• A temporary magnet made from magnetic currents.

What happens when two north poles of a magnet are placed together?

• they repel
• they attract
• they cancel each other out
• the strength of the magnet is doubled

A north pole and a south pole will attract.

• True
• False

True or False: All metals stick to magnets.

• True
• False

Magnets can interact without touching.

• True
• False

Are the magnetic field lines in the picture correct?

• Yes, because they point from north to south.

• No, because they point from north to south (they're supposed to go the other way).

• Yes, because the North pole is on the left in all pictures.

• No, because the North pole is on the left in all pictures (it's supposed to be on the right).

Looking at the field lines in this picture, these two magnets are ________

• Attracting

• Repelling

• Attracting and Repelling

• Doing nothing