6.4 Electromagnets, Motors and Generators

Question 1

what is a magnetic field?

Answer 1

an invisible force field around a permanent magnet

Question 2

what poles attract and repel?

Answer 2

N/S attract, S/S AND N/N repel

Question 3

what are field lines?

Answer 3

field lines show the direction of the force on iron filings and compass needles.

Question 4

what is electromagnetism?

Answer 4

when compasses are placed around the wire, their needles align with the magnetic field around the wire.

Question 5

what is a solenoid?

Answer 5

a looped, current-carrying coil with a strong magnetic field down its core

Question 6

what is an electromagnet?

Answer 6

a solenoid with a rod placed down its core

Question 7

what can an electromagnet do?

Answer 7

• turn on and off
• Can be altered by changing its current
• Can be changed by changing the direction of the current passing through

Question 8

What can a permanent magnet do?

Answer 8

• always on
• cant be adjusted
• Can only be changed by flipping the magnet end to end

Question 9

how are electromagnets used in electricity?

Answer 9

When too much current flows through a house circuit, electromagnets in circuit breakers pull the switch open. This breaks the current running through it.

Question 10

Electric motor needs and produce

Answer 10

• needs a coil, magnet, and an electric current

- produces spinning movement

Question 11

generator needs and produce

Answer 11

• needs a coil, magnet, and a spinning movement

- produces an electric current

Question 12

what is a dynamo?

Answer 12

a small generator that spins its magnets instead of its coils

Question 13

what is a turbine?

Answer 13

a large-scale electricity generator

Question 14

Ways water can spin a turbine:

Answer 14

Hydro-electricity
Wave power
Tidalpower