8th grade Unit 8.3 Quarterly Exam

Ava puts two magnetic toy trains very close to each other on a track. What will happen next and why?

Sound is produced by -----

• Heat energy
• Low temperatures
• Vibrations
• Friction

Sound needs a medium.

• True
• False

Sound waves travel the fastest through ---

• Liquids
• Gases
• Solids

A sound wave cannot travel through which of the following?

• Metal
• Water
• Air
• Vacuum

What do magnets stick to?

• copper
• wood
• iron
• plastic

What would increase the strength of an electromagnet?

• Increasing the number of coils of wire
• Inserting a wooden core inside the coil
• Changing the direction of the current
• Decreasing the number of coils of wire

This is a magnet made by an electric current

• emporary
• permanent
• electromagnet
• ferromagnet

The strongest part of a magnet is...

• the bars.
• the force field.
• the poles.
• the middle.

Are ALL metals magnetic?

• Yes
• No
• No one knows
• Sometimes