Science 4 - Unit 12

What causes static electricity?

• only an object losing electrons

• only an object gaining electrons

• when positive and negative charges balance

• when positive and negative charges no longer balance

Choose the terms that belong in the sentence.

A ____ object ____ a positively charged object.

• neutrally charged, repels

• positively charged, repels

• negatively charged, repels

• positively charged, attracts

Which of the following would be a good conductor for a closed circuit?

• wood

• copper

• rubber

• plastic

Where is a magnetic field the strongest?

• at both poles

• in the middle

• at the south-seeking pole

• at the north-seeking pole

A material that conducts electric current poorly is called

• a circuit

• a charge

• a conductor

• an insulator

Look at the picture. What would happen to the other light bulbs in the circuit if one light bulb burns out?

• The other light bulbs will remain on.

• The other light bulbs will be brighter.

• The other light bulbs will be dimmer.

• The other light bulbs will go out.

Why does a compass needle point in a north-south direction?

• The needle reacts to Earth's magnetic poles.

• The needle forms an electromagnet with Earth's poles.

• The needle is lightweight, so it always spins to the south.

• The needle is pulled in the middle by Earth's equator.

Choose the terms that belong in the sentence.

In a doorbell, electromagnets help convert ____ to _____ to ___________ .

• magnetic energy, electric energy, mechanical energy

• electric energy, magnetic energy, mechanical energy

• electric energy, mechanical energy, magnetic energy

• mechanical energy, magnetic energy, electric energy

How can the strength of an electromagnet be increased?

• by using less current

• by using a smaller magnet

• by using a smaller magnetic core

• by using more turns in the metal coil

What did Michael Faraday do when he discovered that changing a magnetic field created an electric current in a wire?

• He told no one of his investigation.

• He did not think he had discovered anything.

• He shared his investigation with other scientists.

• He told only Joseph Henry about his investigation.