Understanding Electromagnets

Who discovered that electric currents create magnetic fields?

• William Sturgeon

• Hans Christian Ørsted

• Michael Faraday

• Nikola Tesla

Fill in the blank: A ferromagnetic material is a metal or an alloy of metals which can become _______ under the action of a magnetic field.

• A) demagnetized

• B) magnetized

• C) electrified

• D) neutralized

What type of energy is used to send current into an electromagnet?

• Mechanical energy

• Electrical energy

• Sound energy

• Magnetic energy

In computer science, electromagnets are found in ______.

• Speakers

• Hard drives

• Monitors

• Keyboards

What happens when you press the button on a remote control for unlocking car doors?

• It sends a signal to the electronic circuit inside the lock.

• It opens the car door automatically.

• It turns off the car engine.

• It activates the car alarm.

In the kitchen, electromagnets are used in appliances with an electric motor to create a _______ movement.

• Linear

• Rotational

• Circular

• Stationary

Why are electromagnets used in industries?

• To lift heavy loads

• To decorate machines

• To cool down engines

• To paint surfaces

What materials are needed to make an electromagnet?

• Plastic and rubber

• Wood and glass

• Steel or iron nail, copper wire, batteries, paper clips, adhesive tape

• Gold and silver

To make an electromagnet, you need to wrap copper wire around a ______.

• plastic tube

• steel or iron nail

• wooden stick

• glass rod

Which of the following factors can affect the number of paperclips lifted by an electromagnet?

• The type of battery used

• The color of the paperclips

• The size of the table

• The time of day.