Magnetism And Electromagnetism

Question 1

What is a ferromagnetic material

Answer 1

Materials magnetized easily
(Iron,cobalt, manganese)

Question 2

What is a paramagnetic material

Answer 2

Can be magnitized but not as easily as ferromagnetic
(Platinum,titanium,chromium)

Question 3

What is a diamagnetic material?

Answer 3

Things that cannot be magnetized.
(Copper, brass, antimony)

Question 4

What causes magnetism

Answer 4

An imbalance of electron spin

Question 5

What is a magnetic domain

Answer 5

A group of atoms with all their magnetic moments in the same direction

Question 6

What is magnetic moment

Answer 6

An electron that has a greater value than 0 of magnetism in 1 direction

Question 7

What are the two types of magnets

Answer 7

Temporary.
Permanent

Question 8

What is magnetic flux

Answer 8

The lines of force around a magnet

Question 9

What is flux density

Answer 9

The concentration of lines of force around a magnet

Question 10

What is permeability

Answer 10

Describes a material property that decides how much opposition to flux there will be

Question 11

Whats the difference between high permeability and low.

Answer 11

High means flux easily establishes in it. Low means it does not as easily

Question 12

What is reluctance

Answer 12

The opposition from a material to establish a magnetic path

Question 13

What is retentivity

Answer 13

The ability for an item to retain magnetism

Question 14

What is saturation

Answer 14

The point which all domains have been aligned and adding more current will not increase magnetism

Question 15

Do electro magnets use ac or dc mainly

Answer 15

DC

Question 16

What is the left hand rule for conductors

Answer 16

Curve of fingers is lines of force and thumb direction is current flow

Question 17

What does a + represent in terms of current flow

Answer 17

Its flowing away from you

Question 18

What does a dot represent i. Current flow?

Answer 18

Current is flowing towards you

Question 19

What is the left hand rule for coils

Answer 19

Fingers represent current flow and thumb represents the north pole of a magnet

Question 20

What direction does flux flow in a coil

Answer 20

From north to south pole

Question 21

What affects electro magnet strength

Answer 21

Amount of current in the coil
Number of turns in the coil
Type of core used

Question 22

If you double current in an air core coil what happens to magnetism strength

Answer 22

Doubles

Question 23

What are the two common cores of electro magnets

Answer 23

Air and iron

Question 24

Do we want high or low retentivity in the core of an electromagnet?

Answer 24

Low

Question 25

What is hysteresis loss

Answer 25

Energy lost to friction from constantly changing poles from ac circuits in magnets

Question 26

How do we reduce hysteresis loss?

Answer 26

Add silicone to the steel core this reduces friction

Question 27

What is an eddy current

Answer 27

The vtage produced jn the core of an electromagnet due to the changing magnetic field

Question 28

What is eddy current loss

Answer 28

The heat and subsequent energy lost from the currents circulating in the core of a magnet

Question 29

How do we reduce eddy losses?

Answer 29

Making the core out of thin sheets as apposed to a solid core this reduces currents ability to flow

Question 30

What do iron losses inclued

Answer 30

Hysterisis loss and eddy current loss measured in watts

Question 31

What happens once saturation is reached?

Answer 31

Any extra energy is turned to heat