Magnetism and Electromagnets

The material used for constructing the core of an electromagnet is

• iron

• carbon

• copper

• steel.

Which of the following is a major difference between electromagnets and permanent magnets?

• Permanent magnets can be turned on and off, while electromagnets are always producing magnetic fields.

• Electromagnets can be turned on and off, while permanent magnets are always producing magnetic fields.

• Electromagnets are always stronger than permanent magnets.

• Permanent magnets are always larger than electromagnets.

The strongest part of the magnetic field from a magnet is found at the

• farthest region from the magnet

• center of the magnet

• magnet's domains

• magnet's poles

You know this substance is magnetized because

• all the domains have right angles
• the arrows are drawn in red
• the domains are aligned
• the domains are random

What would increase the strength of an electromagnet?

• Changing the direction of the current

• Increased the amount of electricity that flows through the wire.

• Inserting a wooden core inside the coil

• Decreasing the number of coils of wire

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

Generators are devices that convert _____ energy into _____ energy.

• chemical; mechanical
• mechanical; electrical
• electrical; mechanical
• potential; kinetic

In a _______ a spinning turbine moves magnets which generates an electric current.

• Motor

• Generator

What device is made of coils of wire with an electrical current passing through it in order to generate a magnetic field?  

• Electromagnet 
• Generator
• Electron Magnet 
• Motor

What happens to the strength of an electromagnet as you add more coils around it?

• Increases
• Decreases
• Stays the same
• Stops completely