Electromagnetism Quiz

What is an electromagnet?

• A magnet that can be switched on or off

• A magnet that can only attract metal objects

• A magnet that is always on

• A magnet that repels other magnets

What happens to the magnetic field when the electric current is turned off?

• The magnetic field becomes stronger

• The magnetic field disappears

• The magnetic field reverses its direction

• The magnetic field stays the same

What can be done to increase the strength of an electromagnet?

• Increasing the current

• Increasing the number of turns of the coil

• Adding an iron core

• All of the above

What is the purpose of adding an iron core to an electromagnet?

• To make the electromagnet weaker

• To make the electromagnet stronger

• To reverse the direction of the magnetic field

• To prevent the magnetic field from forming

What is a solenoid?

• A type of magnet

• A coil of wire with many turns

• A device that generates electricity

• A material that conducts electricity

What is the shape of the magnetic field around a current-carrying solenoid?

• Circular

• Straight

• Spiral

• Irregular

How does an electromagnet work in a loudspeaker?

• It generates electricity

• It produces sound waves

• It attracts magnetic materials

• It vibrates a cone to create sound

What is the opposite effect of the motor effect?

• The generator effect

• The magnet effect

• The speaker effect

• The microphone effect

What happens when sound waves cause the diaphragm in a microphone to vibrate?

• The microphone generates electricity

• The microphone produces sound waves

• The microphone attracts magnetic materials

• The microphone switches on and off

What is the main use of electromagnets in automatic door locks?

• To generate electricity

• To produce sound waves

• To attract magnetic materials

• To switch the door lock on and off