Terms (1)

Question 1

How do materials become “magnetized”?

Answer 1

ferrous materials placed in strong magnetic fields or have an electrical current flow through them.

Question 2

Degree of magnetization is affected by:

Answer 2

• strength of magnetizing field
• magnetizing properties from material being magnetized
• amount of current flowing in part

Question 3

Define Retentivity

Answer 3

Amount of residual magnetism that a material can hold based on properties after a magnetizing force has been removed.

dependant on:

• material properties
• amount of magnetization material was subjected to

Question 4

Define “residual field”

Answer 4

amount of magnetic field that remains in a material, determined by material retentivity.

Question 5

Define Permeability

Answer 5

Ease a magnetic flux can be established in a given material.

high permeable materials are easier to magnetize.

Question 6

Describe Henrys per meter (H/m)

Answer 6

µ = B/H

µ - permeability
B - flux density
H - magnetizing force

Question 7

Define Reluctance

Answer 7

the degree of opposition of a material to the establishment of a magnetic field/magnetic flux

Low permeability materials = high reluctance = soft iron

Question 8

Define Material Saturation Point

Answer 8

point at which any further increase in magnetizing force would produce no further increase in magnetic flux density.

used to determine true value of retentivity and measure residual flux

Question 9

Define Coersive Force

Answer 9

Reverse magnetizing.

should be = or greater than magnetizing force used to initially magnetize the material.

high retentivity = hardened steel = high coercive force