Physics Unit 3

Question 1

What term is used to describe how easily materials can be magnetized?

Answer 1

Permeability

Question 2

A material that cannot be magnetized because the electrons all spin in different directions is called a_____ material

Answer 2

Non-magnetic

Question 3

When using the left hand thumb rule for straight conductors, the fingers encircling the wire indicate

Answer 3

Direction of magnetic field

Question 4

Materials that are weakly repelled by magnets area classified as what type of magnet

Answer 4

Diamagnetic

Question 5

The term “electromagnetic induction: refers to the production of

Answer 5

An electric current

Question 6

Ferromagnetic

Answer 6

Iron, cobalt, and nickel

Question 7

Nonmagnetic

Answer 7

Wood, plastic, and glass

Question 8

Diamagnetic

Answer 8

Beryllium, bismuth, and lead

Question 9

Paramagnetic

Answer 9

Gadolinium, platinum, and aluminum

Question 10

The north pole of a magnet will be attracted to the north pole of another magnet

Answer 10

False

Question 11

T/F no matter how many pieces a magnet is cut into, each piece will have a north and south pole

Answer 11

True

Question 12

T/F the more closely spaced, the lines of magnetic flux, the weaker the field

Answer 12

False

Question 13

Which person discovered electromagnetic induction

Answer 13

Faraday

Question 14

Which of the following types of magnets are considered temporary

Answer 14

Electromagnets

Question 15

The more coils or numbers of turns a conductor has, the _____ the electromagnetic force

Answer 15

Greater

Question 16

The unit of measurement of magnetic flux is the

Answer 16

Weber

Question 17

Lines of force, on the external surface of a magnet, move from the___pole to the _____pole

Answer 17

North, south

Question 18

A coiled helix, carrying an electrical current is known as a

Answer 18

Solenoid

Question 19

What is the difference between an electromagnet and solenoid?

Answer 19

An electromagnetic has a ferromagnetic core, and a solenoid has no core

Question 20

In a straight conductor, when the conventional current is flowing out of a piece of paper, lying on the table, what direction will the magnetic field be traveling?

Answer 20

Counter clockwise

Question 21

Which of the following statements is true regarding the strength of induced current

Answer 21

The faster the conductor, the stronger the current

Question 22

What principle does the auto transformer work?

Answer 22

Electromagnetic self induction

Question 23

What device varies the voltage that will go to the step up transformer

Answer 23

Auto transformer

Question 24

What is the difference between a step up transformer in the auto transformer?

Answer 24

The auto transformer only has one coil

Question 25

Where is the auto transformer located?

Answer 25

Between the incoming AC and the high voltage transformer

Question 26

There are two separate circuits, supplying the x-ray tube. Which one carries the amperage needed to heat the filament.

Answer 26

Filament circuit

Question 27

Of the two circuits, supplying the tube, which one applies the necessary potential difference across the tube that makes the electrons race from cathode to anode

Answer 27

Filament circuit

Question 28

And auto transformer with primary turns, and 1000 secondary turns, has a turns ratio of

Answer 28

1:2

Question 29

What device is used to increase the amperage to the filament?

Answer 29

Step down transformer

Question 30

What device is used to increase the voltage to kilovoltage ?

Answer 30

Step up transformer

Question 31

What is the terms ratio if a transformer has 40 primary turns and 80 secondary turns

Answer 31

2:1, 80:40

Question 32

A transformer with fewer turns on its secondary coil is a

Answer 32

Step down transformer

Question 33

An auto transformer;

Answer 33

Varies the voltage going to the high voltage transformer

Question 34

An auto transformer can be considered a

Answer 34

KV selector

Question 35

The most efficient type of transformer construction utilized in x-ray equipment is the

Answer 35

Shell type

Question 36

A dynamo is another name for a/an

Answer 36

Electric generator

Question 37

How do generators create energy?

Answer 37

Electromagnetic induction

Question 38

The stronger the magnetic lines are in an electrical generator the;

Answer 38

Stronger the induced current, & the closer the flex lines around the magnet

Question 39

Slip rings and brushes can be found in

Answer 39

An AC generator

Question 40

A generator converts

Answer 40

Mechanical to electrical energy

Question 41

T/F The voltage on the secondary side of a step down transformer is less than on the primary

Answer 41

True

Question 42

T/F the amperage on the secondary side of a step up transformer is greater than on the primary

Answer 42

False

Question 43

T/F the strength of the induced voltage in the secondary coil of a transformer is directly proportional to the number of turns it has in its coil

Answer 43

True

Question 44

T/F a step down transformer, has a turns ratio of greater than one

Answer 44

False

Question 45

T/F a transformer, if you increase voltage, you must increase amperage

Answer 45

False

Question 46

T/F transformers, can operate on AC and DC

Answer 46

False

Question 47

T/F current stays in a constant direction in an AC circuit

Answer 47

False

Question 48

What device in the x-ray machine uses an induction motor

Answer 48

Rotor

Question 49

The type of rectification, where no actual rectifier is added to the circuit is

Answer 49

Self rectification

Question 50

Half wave rectification is inefficient because

Answer 50

It uses only half the available energy of the AC

Question 51

Half wave rectification can be accomplished by using____ or___ diodes

Answer 51

One or two

Question 52

Full wave rectification uses a minimum of_____ solid state diodes to rectify the entire AC in usable energy

Answer 52

4

Question 53

A single phase, fully rectified unit has how much ripple

Answer 53

100%

Question 54

A three phase, 6-pulse fully rectified unit has how much ripple

Answer 54

13%

Question 55

How much ripple does a high frequency, fully rectified unit have

Answer 55

Less than 1%

Question 56

Full rectification uses____ of the available AC

Answer 56

All

Question 57

In three phase energy, the waveforms are out of step with each other by

Answer 57

1/3 of the cycle

Question 58

In order for a solid-state, semi conductor to conduct current, a _____ Change must be applied to the P side of the P-N Junction

Answer 58

Positive

Question 59

In a rectifier,_____ flows with the direction of the arrow

Answer 59

Current

Question 60

Which digit indicates the direction of the current flow

Answer 60

Middle

Question 61

1 A= _____mA

Answer 61

1000

Question 62

1 V= ______kV

Answer 62

.001