Physical Science Unit

A magnet that always keeps its magnetism is known as a ______________.

• bar magnet

• temporary magnet

• permanent magnet

• Electromagnet

Kim is using an electric current to produce a magnetic field. What will happen when she turns off the current?

• The strength of the magnetic field will increase.

• The poles of the magnetic field will reverse.

• The magnetic field will disappear.

• The strength of the magnetic field will change colors.

Read the passage about a magnet. A student performs an investigation. She places a magnet next to a paper clip and watches it quickly become attracted. Next, she moves the magnet farther away, and the paper clip takes a little longer to become attracted. Then, she moves the magnet even farther away from the paper clip. The paper clip does not move. What is the student controlling in this investigation?

• the size of the magnet

• the poles of the magnet

• the direction of the magnetism

• the strength of the magnetic field

Which magnet can be turned on and off?

• bar magnet

• donut magnet

• permanent magnet

• electromagnet

A student is investigating two magnets. The table shows her observations. Which argument can the student make using her data?

• Magnet 1 is an electromagnet that can be turned off.

• Magnet 2 is an electromagnet that can be used outdoors.

• Magnet 1 is a permanent magnet that needs a source of electricity.

• Magnet 2 is a permanent magnet that has an adjustable field strength.

An insulator does not allow electricity to pass through. Which of the following would be a good insulator?

• Penny

• Paper clip

• Cotton ball

• Nail

Margo is running from her bedroom to her sister’s bedroom to watch a movie. She is running so fast she almost falls. When she gets to her sister’s room and opens the door, the doorknob shocks her hand! Which of the following was this an example of?

• Static electricity

• Current electricity

• Heat electricity

• Sound electricity

Which of the following is true about electrical circuits?

• Electricity can only flow if the circuit is a closed loop.

• They have to involve a wire made of insulating material.

• Every circuit needs to have a switch that can stop and start the flow of electricity.

• An open circuit works as long as the wire connects a bulb to the positive end of a battery.

Which of the following items can you replace in a circuit so the light bulb will still light?

• Popsicle stick

• Penny

• Crayon

• Sponge

When you mix vinegar and baking soda, bubbles form because a gas is created. This is an example of a chemical change.

• True

• False