Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics 101-2 (metc) > Lesson 2 > Flashcards

Lesson 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards Psychology 101 flashcards Chemistry 101 flashcards AP® Physics flashcards Biology 101 flashcards Organic Chemistry 101 flashcards Sociology 101 flashcards
1
Q

Rectification

A

process where a AC is changed to DC (oscillating to pulsating)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Rectifier

A

an electronic device that allows electron current to go in one direction. There’s a high resistance to move in the other direction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

X-ray tubes use DC because when using AC the flow of electrons can move in the ______ direction and ______ the tube.

A

wrong , damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

diode

A

a device with 2 electrodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the symbol for a diode?

A

an arrowhead that points in the direction of the current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are diodes typically made of?

A

semiconductors like silicon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 2 types of semiconductors?

A

N-type and P-type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

N-type semiconductors

A

have loosely bound electrons free to move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

P-type semiconductors

A

positive electron traps (holes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

n-type + p-type = ?

Electrons are allowed to flow in?

A

p-n junction

only in one direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

“forward bias” p-n junction

A

current is allowed to flow as holes and electrons go toward each other reducing the barrier voltage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

“reverse bias” p-n junction

A

current flow is prevented as electrons and holes move away from each other and the barrier voltage increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Disadvantage of Self-Rectification?

A

low heat loading capacity of a x-ray tube. The anode can easily overheat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

self-rectification

A

when no rectifier is used and the x-ray tube acts as the “valve tube/diode”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Half-wave rectification

A

“one-pulse” (only positive)
1 voltage peak per cycle (1/2 a normal cycle)
60 pulses per 60 Hz
inefficient- negative half cycle wasted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Full-wave rectification

A

“two-pulse” (both positive and negative)
2 voltage peaks per cycle (a normal cycle)
120 pulses per 60 Hz
more efficient - reverses negative half cycle

17
Q

Full Rectification Advantage

_______ in the power output capability of equipment. Results in ________ __________.

A

Increase , larger exposures

18
Q

Full Rectification Disadvantage

_____ percentage of low energy x-rays

A

high

19
Q

radiographic underexposure

A

one rectifier fails (full wave / 4 rectifiers goes to a two-diode half wave)

20
Q

3 phase power

A

multiple voltage waveforms superimposed for a constant high voltage

21
Q

3 phase , 6 pulse

A

ripple of 13-25%
voltage never drops below 75-87%
35% more “average energy” photons than single phase

22
Q

3 phase , 12 pulse (diodes)

A

ripple of 4-10%
voltage never drops below 90-96%
40% more “average energy” photons than single phase

23
Q

What is the kV ripple for single phase 2 pulse?

A

100%

24
Q

High Frequency (________)

Generators use AC and DC power converters to change the incoming line from ____ to _____.

peak kV is achieved in about ____ of the time needed for 3 phase generators.

What is the kV ripple?

A

Line Voltage

60 Hz to 6000 Hz

10%

3-4%

25
Q

Advantages of 3 phase power when compared to single phase?

A

the lower voltage ripple gives more efficient radiation
less low energy x-rays
greater tube capacity

26
Q

Motor Principle

A

involves the interaction of magnetic fields from a wire with an electric current. There is a force on the wire that pushes it out the field.

27
Q

Galvanometer

A

measures current and voltage, made of copper wire wrapped around a horseshoe magnet

28
Q

Ammeter

A

connected in series and used to measure current

29
Q

Voltmeter

A

connected in parallel and measures potential difference

30
Q

What are the protective devices used to prevent a short circuit fire?

A

ground , fuses , circuit breakers

31
Q

Ground

A

equipment is grounded to the earth to protect x-ray specialist and patient from shock. In a socket typically one hole is for ground, one neutral , and one live)

32
Q

Fuses

A

connected in a series and is not reusable. The metal tab inside melts to end the flow of electrons.

33
Q

circuit breakers

A

pop open once a temperature is reached and can be reused of reset. involves bimetallic strips bending.

34
Q

Autotransformer Law Formula

A

Vs / Vp
(s nd p are subscripts)

# tapped turns 
\_\_\_\_\_\_\_\_\_\_\_\_

primary turns

35
Q

Variable resistor is also know as ?

A

Rheostat or potentiometer

36
Q

Variable resistor

A

Determines how much resistance by manipulating voltage and current

37
Q

Auto transformer

A

Controls the low voltage side on X-ray circuit

Physics 101-2 (metc) (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions