Practice Speakers

When a wire that carries current is placed near a compass, the compass changes direction. This observation indicates

• current in a wire induces voltage

• current in a wire generates a magnetic field

• current in a wire creates electricity

• current in a wire produces resistance

When a wire that carries current is wrapped around a iron nail. This is an example of

• electromagnetic induction

• a circuit

• a permanent magnet

• a electromagnet

A current-carrying wire produces...

• a voltage

• a resistance

• a magnetic field

• a permanent magnet

Permanent magnets are different from electromagnets because... (Select all that apply)

• permanent magnets keep their magnetic field

• permanent magnets are made of materials that have electrons spinning in one direction

• permanent magnets and electromagnets are the same

• none of the options are correct

The strength of an electromagnet depends on... (Select all that apply)

• the amount of voltage pushing current

• the amount of current in the wire

• the number of loops in the coil

• none of the above

A speaker works using the same process as...

• a generator

• a electric motor

• a turbine

• a microphone

A microphone converts ___ to ___ using __.

• sound; electrical current; electromagnetic induction

• sound; electrical current; electromagnets

• electrical current; sound; electromagnetic induction

• electrical current; sound; electromagnets

A speaker converts ___ to ___ using __.

• sound; electrical current; electromagnetic induction

• sound; electrical current; electromagnets

• electrical current; sound; electromagnetic induction

• electrical current; sound; electromagnets

A magnetic field can be created by...

• current

• spinning electrons

• moving charge

• all of the above

An electromagnet and permanent magnet interact using...

• charge

• resistance

• the magnetic force

• electromagnetic induction