A Stronger Electromagnet

A Stronger Electromagnet

Multiple Choice

What is an electromagnet?

• a temporary magnet made from current carrying wire around a magnetic metal core.
• a permanent magnet with a north and south pole

Open Ended

How many uses of permanent magnets or electromagnets can you think of? Go online and find 5 uses now!

Electro magnets have many uses

They are used in electric motors and generators, as well as doorbells and electric switches (called relays)

An engineer needs to be able to design an electromagnet that has got the right strength for the job

Open Ended

Think about the last lesson. How can you make an electromagnet stronger?

Making a stronger electromagnet

• We already know that we can make an electromagnet stronger by adding an iron core

• There are other ways to make it stronger:

• Make a coil with more turns of wire. The wire is longer so when the electric current flows through it, the magnetic field is stronger

Making a stronger electromagnet

• Another way is to make a bigger flow of electric current through the coil of wire. Connect two batteries to the coil instead of one. This will make a larger magnetic field.

• The batteries must be connected end to end as shown in the diagram

Measuring electric current

• If you use two batteries instead of one, you will have twice the amount of electric current in the electromagnet

• We measure electric current with an ammeter

• Electric current is measured in units called amps (symbol: A)

Multiple Choice

This type of magnet is a temporary magnet.

• both

Multiple Choice

This magnet attracts objects made of metal.

• both

Multiple Choice

You can make this magnet stronger.

• both

Multiple Choice

This type of magnet requires electric current.

• both

Multiple Choice

This magnet has both a south pole and a north pole.

• both

Multiple Choice

This type of magnet is a permanent magnet

• both

Multiple Choice

What are the components of the electromagnet?

• copper wire, iron nail, and a wooden stick

• copper wire, iron nail

• copper wire, iron nail, and a battery

• Copper wire, paper and a battery

Multiple Choice

You can make an electromagnet stronger by: having a __________________core inside the wire.

• smaller core

• larger core

• greener core

• water core

Multiple Choice

Which component provides the energy or the power source to run the electromagnet?

• Iron nail

• wire

• Switch

• Battery

Multiple Choice

What component becomes a temporary magnet when electricity is flowing through the circuit?

• iron nail

• copper wire

• battery

• switch

Multiple Choice

The strength of the magnetic field of a electromagnet can be increased by

• Decreasing the number of coils.
• Increasing the number of coils
• Decreasing the current
• Increasing the resistance

Multiple Choice

  You can make an electromagnet stronger by: having a __________________ current in the wire

• smaller
• larger
• greener
• water

Multiple Choice

What would increase the strength of an electromagnet?

• Increasing the amount of current flowing through the wire.
• Inserting a wooden core inside the coil
• Changing the direction of the current
• Decreasing the number of coils of wire

Multiple Choice

Surrounding every magnet is a __________  __________.

• magnetic field
• electrical current
• another magnet

Multiple Choice

How are electromagnets different from magnets?

• magnets can be turned on/off
• you can turn an electromagnet on/off
• magnets are more powerful
• magnets have a North and South pole

Multiple Choice

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.