3. Magnetism and Electromagnetism

Question 1

the place where magnets where discovered

Answer 1

Magnesia

Question 2

the one who discovered magnets

Answer 2

Magnese

Question 3

the direction of the magnetic field lines (magnetism) is from north to south but within the magnet the direction is from south to north

Answer 3

Magnetism

Question 4

small magnet created by the electron orbit

Answer 4

Magnetic Dipole

Question 5

an accumulation of many atomic magnets with their dipoles aligned

Answer 5

Magnetic Domain

Question 6

is the ability of a material to attract the lines of magnetic field intensity

Answer 6

Magnetic Permeability

Question 7

CLASSIFICATION OF MAGNETS

Answer 7

• Naturally occurring magnets
• Artificially induced permanent magnets
• Electromagnets

Question 8

consists of wire wrapped around an iron core

Answer 8

Electromagnets

Question 9

do not react to magnetic source (wood)

Answer 9

Nonmagnetic

Question 10

weakly repelled from the magnet (silver and gold)

Answer 10

Diamagnetic

Question 11

highly attracted to magnets (iron)

Answer 11

Ferromagnetic

Question 12

weakly attracted to magnet (contrast media in MRI)

Answer 12

Paramagnetic

Question 13

the degree to which a material can be magnetized

Answer 13

Magnetic Susceptibility

Question 14

MAGNETIC LAWS

Answer 14

• Every magnet, no matter how small, has two poles: north and south
• Like magnetic poles repel and unlike magnetic poles attract
• Ferromagnetic material can be made magnetic when placed in an external magnetic field
• The force between poles is proportional to the product of the magnetic pole strengths divided by the square of the distance between them

Question 15

Unit for Magnetic Strength

Answer 15

SI unit: Tesla (T)

Conventional unit: Gauss (G)

Question 16

One tesla (SI Unit; T) = _____ gauss (Conventional unit; G)

Answer 16

10000 gauss

Question 17

is the force associated with electrons in motion

Answer 17

Electromagnetism

Question 18

made the Voltaic Pile

Answer 18

Alessandro Volta

Question 19

proved that electricity can produce magnetism

Answer 19

Hans Oersted

Question 20

a coil of wire

Answer 20

Solenoid

Question 21

a ferromagnetic material wrapped in a coil of wire

Answer 21

Electromagnet

Question 22

proved that magnets can induce electricity

Answer 22

Michael Faraday

Question 23

Faraday’s experiment. When the switch in the primary circuit is closed, the ammeter in the secondary circuit deflects momentarily. The emf induced in the secondary circuit is caused by the changing magnetic field through the secondary coil

Answer 23

Faraday’s Law of Induction

Question 24

electric current will be induced to flow in a circuit if some part of that circuit is in changing magnetic field

Answer 24

Faraday’s Law

Question 25

THE MAGNITUDE OF THE INDUCED CURRENT DEPENDS ON THE FOLLOWING FOUR FACTORS:

Answer 25

1. The strength of the magnetic field 2. The velocity of the magnetic field as it moves past the conductor 3. The angle of the conductor to the magnetic field 4. The number of turns in the conductor (the higher turns more electricity

Question 26

created the Lenz’ law

Answer 26

Heinrich Lenz

Question 27

induced current flows in a direction such that it opposes the action that induced it

Answer 27

Lenz’ Law

Question 28

2 TYPES OF INDUCTION

Answer 28

1. Self-induction | 2. Mutual induction

Question 29

the induction of an opposing EMF in a single coil by its own changing magnetic field

Answer 29

Self-Induction

Question 30

the process of inducing a current flow through a secondary coil

Answer 30

Mutual Induction

Question 31

Changes mechanical energy into electrical energy

Answer 31

Electric Generator

Question 32

In ________, a coil of wire is placed in a strong magnetic field between two poles of a magnet

Answer 32

electric generator

Question 33

changes electrical energy into mechanical energy

Answer 33

Electric Motor

Question 34

energy is supplied to a series of wire loops

Answer 34

Direct Current Motor

Question 35

energy is supplied to the external magnets

Answer 35

Induction Motor

Question 36

The force between poles is ______ to the product of the magnetic pole strengths divided by the square of the ______ between them

Answer 36

proportional, | distance