Deck 6: Magnets and Magnetism

Question 1

Which term describes the ability of a material to retain its magnetism after being removed from the magnetizing influence?

A) residual magnetism
B) retentivity
C) permeability
D) magnetic saturation

Answer 1

B

Question 2

Which term describes the ability of a material to conduct lines of force?

A) residual magnetism
B) retentivity
C) permeability
D) magnetic saturation

Answer 2

C

Question 3

All artificial magnets are permanent magnets.

Answer 3

False

Question 4

Air is the best conductor of magnetism.

Question 5

Which material is often used to protect sensitive instruments from electromagnetic fields?

A) iron
B) nickel
C) alnico
D) steel

Question 6

A(n) ____ produces a magnetic field.

A) electric current
B) coil
C) core
D) armature

Question 7

Because all materials have some ability to conduct magnetic lines of force, it is not practical to make a magnetic insulator.

Question 8

A(n) ____ is also known as an electromagnet.

A) armature
B) magnetite ore fragment
C) coil
D) core

Question 9

The unit of measurement of flux in a magnetic circuit is called the ____.

A) resistance
B) maxwell
C) gilbert
D) reluctance

Question 10

One of the most common types of permanent magnets is made of ____.

A) iron
B) nickel
C) alnico
D) steel

Question 11

Using the left-hand rule for a single conductor, with your left hand around the conductor with thumb extended in the direction of current flow, the fingers will point in the direction of the ____.

A) electromotive force
B) current
C) magnet's south pole
D) lines of force of the magnetic field

Question 12

There are three classes of magnets: natural, artificial and electromagnets.

Question 13

If two conductors carrying current in the same direction are placed near each other, the magnetic forces tend to ____.

A) push them apart
B) pull them together
C) have no effect
D) cancel each other out

Question 14

Which term describes magnetism that remains in a material after being removed from the magnetizing influence?

A) residual magnetism
B) retentivity
C) permeability
D) magnetic saturation

Question 15

The two main theories of magnetism are the molecular and electron theories.