Fields, Currents and Floating Trains: teacher key

Magnets, grade 7 edition, written for 7th grade. How electricity makes magnets, how trains float on them, and how Earth is one.

Read the book. Print this page for the key.

Questions and answers

Why does gravity have no poles?
- Its pull points up
- The gravity from every part just adds together (answer)
- It is too weak
Which two kinds of magnets exist?
- Permanent and temporary (answer)
- Hot and cold
- Iron and wood
What does a changing magnetic field near a conductor create?
- A new magnet
- An electric current (answer)
- A compass
What drives a Maglev train?
- Wind
- A steam engine
- The powered guideway (answer)
Why might an electromagnet be useful?
- It can be far stronger than the strongest permanent magnet (answer)
- It never needs power
- It can be made of paper