Magnetism and Electricity

Which of these things will make an electromagnet stronger?

• Decrease the current flowing through the coil.

• Reduce the turns of the coil around the iron core.

• Wrap the coil around a smaller iron core.

• Increase the current flowing through the coil.

Two electromagnets contain the same types of magnets and wires, but the magnet in the first moves much faster than the second. Therefore:

• The first electromagnet has a more powerful current than the second

• The first electromagnet has a less powerful current than the second.

• The currents in the two electromagnets run in opposite directions.

• The currents in the two electromagnets run in the same direction.

What would we call a nail that can pick up a paperclip because it is touching a magnet?

• Temporary magnet

• force

• poles

• detector

Students attached both ends of a long wire to the poles of a battery and wound the wire around a spoon. They found that the spoon will now pick up small objects made of iron. This is because the flow of electricity is able to produce:

• a sound wave

• light energy

• thermal energy

• a magnetic field

Bar magnets are different from electromagnets because bar magnets:

• require electricity to produce a magnetic field

• maintain a magnetic field at all times

• produce a magnetic field only when pointed north

• stop being a magnetic near other magnets

Students place paper clips on a desk, and then hold a magnet under the desk. What evidence would best show that the magnetic field was able to pass through the desk?

• The students were able to pick up these paper clips with a magnet.

• The top of the desk is made of a kind of plastic.

• The magnet they are using is the largest one in the classroom.

• The paper clips move when the magnet is moved under the desk.

Surrounding every magnet is a/an ___________ _____________

• Another magnet

• magnetic field

• electrical current

• power source

Which of the following is NOT part of an electromagnet?

• Toothpick

• Wire

• Power Source

• Iron

A push or a pull

• electromagnet

• temporary magnet

• force

• magnet

A magnet that can be turned on and off, where the magnetic field is produced by electrical current

• Magnet

• force

• temporary magnet

• electromagnet