Magnetism & Electromagnetism

Question 0

Lines of force in space called flux

Answer 0

Magnetic field

Question 1

The ability of a material to attract iron, cobalt, or nickel

Answer 1

Magnetism

Question 2

Which way do the lines of flux travel on the inside of a magnet?

On the outside?

Answer 2

South Pole to North Pole

North Pole to South Pole

Question 3

What happens when the lines of flux travel in the same direction?

Opposite direction?

Answer 3

Repel

Attract

Question 4

What are magnetic fields distorted by?

What are magnetic fields unaffected by?

Answer 4

Magnetic materials

Non-magnetic materials

Question 5

What are the 3 laws of magnetism?

Answer 5

1. Every magnet has a North and South Pole
2. Like poles repel each other and opposite poles attract each other
3. Inverse square law

Question 6

What are the 4 categories of magnetic properties?

Answer 6

Nonmagnetic
Diamagnetic
Paramagnetic
Ferromagnetic

Question 7

Not attracted to magnetic fields (glass, wood, plastic)

Answer 7

Nonmagnetic

Question 8

Repelled by magnetic field (water, mercury, gold)

Answer 8

Diamagnetic

Question 9

Feebly attracted to magnetic fields (platinum, gadolinium)

Answer 9

Paramagnetic

Question 10

Strongly attracted to magnetic fields (iron, cobalt, nickel)

Answer 10

Ferromagnetic

Question 11

Electricity and magnetism forces

Answer 11

Electromagnetism

Question 12

What are the 3 main types of magnets?

Answer 12

Natural magnets
Artificial/Permanent magnets
Electromagnets

Question 13

Example: Refrigerator magnet

Answer 13

Artificial/permanent magnet

Question 14

Is only a magnet when electricity is flowing through it

Answer 14

Electromagnet

Question 15

What is the SI unit of magnetic field strength?

Answer 15

Tesla

Question 16

What are some other ways to say ‘magnetic fields’?

Answer 16

Zone of influence
Lines of force
Magnetic flux

Question 17

The more closely spaced magnetic fields are, what happens to them?

Answer 17

They become stronger

Question 18

What creates a magnetic field?

Answer 18

Electricity

Question 19

The branch of physics that deals with the relationship between electricity and magnetism

Answer 19

Electromagnetism

Question 20

Which experiment demonstrates Lines of Force?

Answer 20

Davy’s

Question 21

When does a magnetic field exist around a wire?

Answer 21

When there is an electric current flowing

Question 22

What is another name for electromotive force?

Answer 22

Electric potential

Question 23

Higher voltage the higher potential to do work

Answer 23

Electrical potential

Question 24

A device that converts some form of energy directly into electric energy is said to be a source of _____.

Answer 24

Electromotive force (EMF)

Question 25

A coiled wire (helix)

Answer 25

Solenoid

Question 26

What will further intensify a magnetic field?

Answer 26

Inserting a magnetic material (iron) within solenoid

Question 27

Can magnetic field generate electricity?

Answer 27

Under certain conditions

Question 28

What is the first law of electromagnetic induction?

Answer 28

A moving magnetic field can create an electric current

Question 29

What happens when a wire is cut across the lines of a magnetic field?

Answer 29

Electricity is induced

Question 30

Which 4 factors determine induced electromotive force?

Answer 30

Speed Strength Angle # of turns

Question 31

What are the 3 ways to induce an electromotive force,or voltage, in a wire?

Answer 31

1. The wire may move across a stationary magnetic flux 2. The magnetic flux may move across a stationary wire 3. The magnetic flux may vary in strength while a stationary wire lies in it

Question 32

What is the diagnostic range for kVp?

Answer 32

30-150

Question 33

What is the 2nd law electromagnetic induction?

Answer 33

The induced current will flow in the opposite direction of the action that induces it

Question 34

What are the 2 types of induction?

Answer 34

Self-induction | Mutual induction

Question 35

Process by which the magnetic field of a coil induces a counter EMF in the coil itself

Answer 35

Self-Induction

Question 36

Which type of induction uses autotransformers?

Answer 36

Self-Induction

Question 37

Inducing a current flow through the secondary coil by passing a changing current through the primary coil

Answer 37

Mutual induction

Question 38

True or false. The first coil is always the primary coil.

Answer 38

True

Question 39

Electrical energy to mechanical energy

Answer 39

Electrical motors

Question 40

Mechanical energy to electrical energy

Answer 40

Generators

Question 41

What is essential to electromagnetic induction?

Answer 41

The intensity of the magnetic field at the coil must be changing to induce a current flow

Question 42

A device that changes an alternating current from low-voltage to high-voltage or from high-voltage to low-voltage

Answer 42

Transformers

Question 43

Are Transformers 100% effective?

Answer 43

Not normally. Usually 90%-95%

Question 44

More turns in secondary coil than in primary coil

Answer 44

Step-up transformer

Question 45

Fewer turns in secondary coil than in primary coil

Answer 45

Step-down transformer

Question 46

If you increase the # of turns, what happens to voltage? What happens to amperage?

Answer 46

Voltage increases Amperage decreases

Question 47

If you decrease number of turns, what happens to voltage? What happens to amperage?

Answer 47

Voltage decreases Amperage increases

Question 48

What are the three types of transformers?

Answer 48

Closed core Shell type Autotransformer

Question 49

What are the 3 types of energy losses?

Answer 49

Resistance Hysteresis Eddy Currents