3rd grade electricity and magnetism

Example

What happens if you add a second bulb in series with the first (same cell)?

1. Two bulbs in series share the voltage, so each is dimmer.
2. So the answer is: Both bulbs are dimmer

Answer: Both bulbs are dimmer

Example

If you put a wooden spoon in the gap in a circuit, would it conduct electricity or insulate?

1. Electrical insulators do not let current flow.
2. So the answer is: insulator

Answer: insulator

Example

The south pole of one magnet is brought near the north pole of another. Do they attract or repel?

1. They are opposite poles.
2. So the answer is: attract

Answer: attract

Example

You hold two bar magnets so that the south pole of one faces the south pole of the other. What happens?

1. south and south are the same pole, so they repel.
2. So the answer is: repel (push apart)

Answer: repel (push apart)

Example

A magnet still pulls a paperclip through a sheet of paper. What does this show?

1. Magnetism is a non-contact force that can pass through paper, plastic and water.
2. So the answer is: Magnetic force can act through some materials and across a gap.

Answer: Magnetic force can act through some materials and across a gap.

Example

A recycling centre needs to separate steel cans from aluminium (aluminum) cans. What should it use?

1. Steel contains iron, so it is magnetic; aluminium is not.
2. So the answer is: a big magnet that picks out the steel cans

Answer: a big magnet that picks out the steel cans

Example

You rub a balloon on your hair and hold it near your head. Your hair lifts towards it. Why?

1. The balloon gains negative charge, the hair is left positive, and opposite charges attract.
2. So the answer is: Rubbing gave the balloon and hair opposite electric charges, which attract.

Answer: Rubbing gave the balloon and hair opposite electric charges, which attract.