# Magnets and electromagnets

> Grade 8: magnetic fields, Earth's magnetic field and compasses, magnetic materials (iron, nickel, cobalt), electromagnets, making an electromagnet stronger.

Source: https://olyclass.com/library/science-g8-magnetism-en/

- Subject: Science
- Level: Grade 8
- Quiz: 16
- Play it free on one screen (projector, TV or whiteboard): https://olyclass.com/library?play=science-g8-magnetism-en
- Copy and edit it: https://olyclass.com/library?copy=science-g8-magnetism-en
- Games it plays well in: [Dare Board](https://olyclass.com/classroom-games/dare-board/), [Prize Climb](https://olyclass.com/classroom-games/prize-climb/), [Ring the Bell](https://olyclass.com/classroom-games/ring-the-bell/), [High Water](https://olyclass.com/classroom-games/high-water/)

## Questions

1. What do we call the area around a magnet where it can push or pull? (Magnetic circuit / Magnetic field / Magnetic shield / Magnetic surface)
   Answer: Magnetic field
2. Where are the magnetic field lines of a bar magnet closest together? (At the middle / At the poles / Far from the magnet / Only on one side)
   Answer: At the poles
3. Two north poles placed close together repel each other.
   Answer: True
4. Outside a bar magnet, field lines are drawn pointing from which pole to which? (East to west / North to north / North to south / South to north)
   Answer: North to south
5. What is a compass needle? (A piece of copper / A piece of plastic / A small magnet / A tiny battery)
   Answer: A small magnet
6. Which geographic direction does a compass needle's north-seeking end point to?
   Answer: Geographic north
7. Earth behaves as if it has a giant bar magnet inside it.
   Answer: True
8. Which of these metals is magnetic? (Aluminium / Copper / Gold / Nickel)
   Answer: Nickel
9. Which list contains only magnetic metals? (Cobalt, gold, aluminium / Iron, copper, zinc / Iron, nickel, cobalt / Nickel, silver, tin)
   Answer: Iron, nickel, cobalt
10. All metals are attracted to magnets.
   Answer: False
11. What is an electromagnet? (A magnet made by electric current / A magnet made by heating iron / A magnet made from plastic / A magnet that needs no energy)
   Answer: A magnet made by electric current
12. Which core is best for a simple electromagnet? (A copper nail / A plastic rod / A wooden stick / An iron nail)
   Answer: An iron nail
13. What happens to an electromagnet when the current is switched off? (It becomes stronger / It loses its magnetism / It turns into iron / Its poles swap forever)
   Answer: It loses its magnetism
14. Which change makes an electromagnet stronger? (Fewer turns of wire / More turns of wire / Using a weaker battery / Using a wooden core)
   Answer: More turns of wire
15. Name one change to the current that makes an electromagnet stronger.
   Answer: Increase the current (more cells or higher voltage)
16. How can you reverse the poles of an electromagnet?
   Answer: Reverse the direction of the current (swap battery connections)