Week 8

Question 1

Magnetic Force

Answer 1

the power that pulls materials together.

Question 2

Magnetic Pole

Answer 2

each of the points near the extremities of the axis of rotation of the earth or another celestial body where a magnetic needle dips vertically.

Question 3

Magnetic Field

Answer 3

a region around a magnetic material or a moving electric charge within which the force of magnetism acts.

Question 4

Magnetic Field Intensity

Answer 4

the vector sum of all the forces exerted by a magnetic field at a given point in the field

Question 5

Magnetic Domain

Answer 5

region in which the magnetic fields of atoms are grouped together and aligned.

Question 6

Ferromagnetic

Answer 6

having a high susceptibility to magnetization, the strength of which depends on that of the applied magnetizing field, and which may persist after removal of the applied field.

Question 7

Retentivity

Answer 7

the ability of a substance to retain or resist magnetization

Question 8

Permanent Magnet

Answer 8

a magnet that retains its magnetic properties in the absence of an inducing field or current.

Question 9

Electromagnet

Answer 9

a soft metal core made into a magnet by the passage of electric current through a coil surrounding it.

Question 10

Solenoid

Answer 10

a cylindrical coil of wire acting as a magnet when carrying electric current.

Question 11

Electric Motor

Answer 11

an electrical machine that converts electrical energy into mechanical energy.

Question 12

Electromagnetic Induction

Answer 12

production of an electromotive force across a conductor exposed to time varying magnetic fields.

Question 13

Flux

Answer 13

the action or process of flowing or flowing out.

Question 14

Flux Linkage

Answer 14

the flux density passing through the loop multiplied by its surface area

Question 15

Generator

Answer 15

a dynamo or similar machine for converting mechanical energy into electricity.

Question 16

Motor Effect

Answer 16

a current-carrying wire in the presence of a magnetic field experiences a force

Question 17

Transformer

Answer 17

an apparatus for reducing or increasing the voltage of an alternating current

Question 18

Self-induction

Answer 18

the induction of an electromotive force in a circuit when the current in that circuit is varied

Question 19

Back EMF (back electromotive force)

Answer 19

refer to the voltage that occurs in electric motors where there is relative motion between the armature of the motor and the magnetic field from the motor’s field magnets