When is a magnetic field produced around a wire?

What are the three ways in which we can strengthen the magnetic field around a wire?

What two things are needed to produce an electric current?

What is electromagnetic induction?

Give two ways the direction of voltage can be reversed.

When only is voltage produced?

What do field line patterns show?

What are field line patterns usually drawn with?

What do the arrows on field line diagrams represent?

What is a solenoid?

How do you increase the induced voltage?

Define the motor effect.

How can a simple electric motor be constructed?

Explain how a motor works.

What must be done to prevent the coil coming to a halt?

What do speakers contain both of?

Explain how a speaker works.