June 9th Exam Practice 2

How do you increase the strength of an electromagnet?

• Decrease the number of batteries and increase the number of coils
• Increase the electric current and decrease the batteries
• You cannot strengthen an electromagnet
• Increase the electric current and increase the number of coils

How are electromagnets different from regular magnets?

• Their strength can be changed
• They can be turned on and off
• Their polarity can be reversed
• All choices are correct

A machine that converts electrical energy into mechanical energy.

• Generator
• Motor
• Parallel circuit
• Ohm

What makes an electromagnet stronger?

• Increase the number of wire wraps around the iron core
• decrease the strength of the power source
• remove the source of current
• lightning bolts hitting a tree

What is the relationship between electrical current and magnetic field strength in an electromagnet?

• When current is increased, magnetic field strength increases
• When current is increased the strength of magnetic field decreases
• When the current is decreased, the strenght of the magnetic field is increased.
• There is an "indirect proportion," meaning, if the value of one goes up, the value of the other goes down.

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.

What does a motor do?

• Moves up and down
• Rotates without Electricity 
• It does
• Uses Electricity to cause motion (usually, rotational motion)

What is the job of the generator in a coal power plant?

• Use electrical energy to turn a turbine.
• Convert electrical energy into mechanical energy
• Turn the turbine which changes water into steam
• To change mechanical energy into electrical energy

This transforms mechanical energy into electrical energy.

• Generator
• Electromagnet
• Motor
• Circuit

What is the transfer of electricity in a motor?

• chemical to mechanical 
• electrical to mechanical
• mechanical to electrical 
• physical to potential