Deck 6: Magnets and Magnetism

Question 1

All artificial magnets are permanent magnets.

Answer 1

False

Question 2

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

Answer 2

B

Question 3

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

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

Answer 3

C

Question 4

The three classes of magnets are natural, artificial, and electromagnets.

Question 5

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

Question 6

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

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

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

According to the left-hand rule for a single conductor, when grasping a conductor in your left hand with your thumb extended in the direction of current flow, your 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 9

According to the electron theory of magnetism, electrons produce a magnetic field as they spin.

Question 10

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

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

Question 11

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

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

Question 12

Air is the best conductor of magnetism.

Question 13

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

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

Question 14

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

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

Question 15

A(n) ____ produces a magnetic field.

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