Magnetism

Question 1

____ are where the magnetic lines of force enter and leave the magnet

Answer 1

poles

Question 2

______ pole always points to ______ pole

Answer 2

North points to South

Question 3

Magnetic lines of force always complete _____ and cannot cross

Answer 3

loops

Question 4

Name two magnetic materials

Answer 4

Iron and Steel

Question 5

Any material that behaves like iron in a magnetic field is known as a _____________ material

Answer 5

ferromagnetic

Question 6

Flux density refers to the number of lines of force, more lines means a stronger magnet. True or False?

Answer 6

True

Question 7

What is an example of a natural magnet?

Answer 7

Loadstone (Magnetite)

Question 8

What is an example of an artificial magnet?

Answer 8

Iron, Nickel, and Cobalt

Question 9

Factors that affect the strength of an Electromagnet; (4)

Answer 9

1. Number of turns
2. Spacing between turns
3. Type of material used
4. Amount of current flow

Question 10

Reluctance is the property that opposes the setting up of ____ ____

Answer 10

flux lines

Question 11

Soft iron has ____ reluctance and is easily magnetized

Answer 11

low

Question 12

Methods of demagnetizing? (3)

Answer 12

1. Use of current
2. Heat
3. Vibration

Question 13

Precaution to avoid damaging magnets (4)

Answer 13

1. No heat
2. No vibration
3. No AC current
4. Don’t store near another magnet

Question 14

What is a Keeper?

Answer 14

piece of soft iron placed across the poles to provide an easy path for flux

Question 15

Lines of force flow from N-S on the _____ of there magnet

Answer 15

outside

Question 16

Lines of force flow from S-N on the _____ of there magnet

Answer 16

inside

Question 17

Opposites ______ and Like charges ______

Answer 17

Attract

Repel

Question 18

Magnetic lines of force flow which direction?

Answer 18

directionless unless you have poles

Question 19

What happens to the lines of force when current stops?

Answer 19

They collapse inward