Definitions
What is an electromagnet?
An electric current creates a temporary magnet.
Electromagnetism is the relationship between electricity and ____.
magnetism
Why do people take the time to build an electromagnet?
A. They are a fun toy to play with
B. They are very dangerous and people like to build them because of the adrenaline
C. People use them in everyday life for various items
D. None of the above
C is the correct answer
Where do you put the tips of the wire on the battery?
You should put one end of the wire on the top of the positive side and the other tip of the wire on the bottom of the negative side.
How important are electromagnets for hard drive disks?
Electromagnets are very important for hard drive disks because the magnetic field is vital for the disk to work.
What is a magnetic field?
The area of magnetic force around a magnet.
Anything that has an electric ___ flowing through it is surrounded by an magnetic field.
current
Which item is needed to build an electromagnet?
A. A paperclip
B. A nail
C. A magnet
D. A magnetic field
B is correct.
What do you need when building an electromagnet?
When building an electromagnet, you need a battery, a wire, and a solenoid like a nail.
Does an MRI machine use an electromagnet in it to work?
Yes, an electromagnet is used in an MRI machine because a magnetic field is used to align protons.
What is a current?
The movement of charges.
A compass field responds to a _________ because the compass needle is a magnet (two words).
magnetic field
What is true about electromagnets? Choose all that apply.
A. they are permanent
B. they work because of magnetic currents
C. they work because of electric currents
D. they are temporary
C and D are correct.
What will happen to the magnetic field if a ferromagnetic material is stronger?
The magnetic field will also become stronger and bigger.
What is something that needs an electromagnet to work that involves sound?
headphones/earbuds/speaker
What is a solenoid?
A ferromagnetic material with a current running through it.
When a circuit is ___ the object loses its magnetism.
opened
Why must a wire form a closed circuit?
A. So the current can flow over the wire
B. So the current can flow under the wire
C. So the current can flow through the wire
D. So the current can temporarily not flow through the wire
C is correct.
What type of material do you need to wrap your wire around?
You need an object that can be magnetic, such as something iron or nickel.
How does a generator work?
An electromagnet is working through the generator and causes it to work.
What is voltage?
A power source that provides a force that moves charges around an electric circuit.
A current causes ___ to line up and boost the strength of magnetic forces.
domains
If electromagnet 1 has a battery with four volts and a wire wrapped around a nail twenty times, is that more magnetic than electromagnet 2 which has a battery with two volts and a wire wrapped around a nail fifteen times?
A. No, even though the electromagnet 1 has a batter with more volts, the wrappings around the nails mean the electric current is more sufficient.
B. Yes, since electromagnet 1 has a battery with more volts and a wire with more coils, it is more magnetic.
C. Yes, electromagnet 1 has a battery with more volts and the amount of coils in the wire does not matter.
D. No, they are both magnetically balanced.
B is the correct answer.
If an electromagnet can hold more than 50 paper clips, what assumption can you make about the electric current?
The electric current is moving very fast.
Why does a junkyard crane use an electromagnet to work?
The electromagnet magnetizes the crane's head and when needs to drop objects where they need to, they can just turn the electromagnet off because it is temporary.