Magnetic Terms (1)

Question 1

Permeability

Answer 1

u = B/H

u - permeability
B - flux density
H - magnetizing force

Question 2

Define Permeability

Answer 2

the ease at which a magnetic flux is established in a given material unit

• u
• Henrys per Meter

Question 3

Define magnetizing force

Answer 3

the magnetizing field applied to a ferromagnetic material to induce magnetization.

• H
• Ampere/meter (oersted)

Question 4

Define magnetic flux

Answer 4

total number of lines of force existing in a magnetic circuit
- weber (maxwell)

Question 5

Define magnetic flux density

Answer 5

strength of a magnetic field expressed in the number of flux lines passing transversely through a unit area

• B
• Tesla (Gauss)

Question 6

Define saturation point

Answer 6

the point at which a further increase in magnetizing force will produces no further flux density

Question 7

Define Reluctance

Answer 7

• opposition of a material to establish a magnetic flux
• determines magnitude of flux produces by a given magnetizing force

high reluctance = hard steel = low permeability

Question 8

Define retentivity

Answer 8

• Ability of a material to retain magnetism after force is removed
• measure of residual flux corresponding to saturation point

high retentivity = hard steel = high coercive force

Question 9

Define residual magnetism

Answer 9

flux density that remains in a material when the magnetizing force is zero

Question 10

define coercive force

Answer 10

reverse magnetic field required to reduce magnetization to zero

Question 11

define hysteresis

Answer 11

the lagging of the magnetic effect when a magnetizing force acting upon a ferromagnetic material is changed