physics chapter 4 part 2 Flashcards

0
Q

Parts of the secondary circuit

A

Secondary side of step up transformer, the milliamperage meter, a rectifier bank, and the X-ray tube

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

Parts of the primary circuit

A

Consists if the main power switch(connected to incoming power supply), circuit breakers, the auto transformer, the timer circuit, and the primary side of the step up transformer

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

Parts of the filament circuit

A

Rheostat, step down transformer and the filaments

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

Know what causes the pulsation in a single phase circuit

A

The alternating change in voltage from zero to maximum potential 120 times each second in a full wave rectified circuit

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

Know how a 3 phase circuit or 3 phase power works

A

Six pulse circuit requires 6 rectifies to produce six usable pulses per cycle, 12 pulse circuit requires 12 rectifies to produce 12 useable pulses per cycle

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

What does the 3 phase provide?

A

More efficient xray production

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

Know what the end result will be for 3 phase

A

Wave form which never reaches zero, thereby providing an increased voltage

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

Why circuit breakers are included within a circuit

A

To protect against short circuits and electric shock

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

What are auto transformers

A

An adjustable transformer controlled by the kilovoltage peak selector on the operating console

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

How does the radiographer control the autotransformer

A

When radiographer selects a kVp setting

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

What does the autotransformer operates under?

A

Principle of self induction

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

Why is an autotransformer sometimes balled kVp selector

A

Because of its function

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

What’s an autotransformers primary purpose

A

To provide a voltage that will bE increased by the step up transformer to produce the kilovoltage selected at the operating console

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

What does the step up transformer in the primary circuit change?

A

◾️increase voltage from autotansformer to kVp necessary for xray production
◾️alternating current from low voltage to high voltage

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

What is the step up transformer in the primary circuit a dividing line of?

A

Between the primary and secondary circuits

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

Where the 2 parts of the step up transformer in the primary circuit are located?

A

◾️primary coil ➡️ primary circuit

◾️secondary coil➡️secondary circuit

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

How does the step up transformer differ from the autotansformer

A

This transformer is not adjustable and increase the voltage from the autotransformer by a fixed amount

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why is the exposure timer located in the primary circuit?

A

It’s easier to control (turn in or off) a low voltage than a very high one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

First variation of timer and explain it

A

Synchronous timer➡️ based on a synchronous meter

19
Q

Second variation of timer and explain it

A

Electronic timer➡️ very sophisticated and accurate timer that is most widely used today based on the time it takes to charge a capacitor.

20
Q

Third variation of timer and explain it

A

mAs timer- variation of electronic timer, but it monitors the current passing through the X-ray tube and terminates the exposure when the desired mAs is reached. Located in the secondary circuit.

21
Q

Know how the aec works differently than an exposure timer

A

Uses the patient body part of interest as the variable in determining when to terminate exposure. AEC uses a device called the ionization chamber.

22
Q

What AEC controls

A

Only the quantity of radiation reaching the IR and therefore has no effect on other image characteristics such as contrast

23
Q

Know what secondary circuit begins with

A

The rest of the step up transformer

24
Q

Know what the milliampere meter is

A

A device placed in the secondary circuit that monitors X-ray tube current

25
Q

Know where and why the tube is grounded

A

To prevent electrical shock ➡️ secondary circuit

26
Q

What rectifiers are

A

Convert AC ➡️ DC allows current to flow from anode ➡️ cathode and electrons from cathode to anode. Made of two semi-conducting crystals

27
Q

Which rectifiers are commonly used today

A

Solid state rectifier

28
Q

How we get the best use of rectifiers

A

Arranged in pairs so that the AC cycle has an open “path” from each direction

29
Q

Know the type of current needed for transformer

A

AC

30
Q

What current must supply X-ray tube

A

DC

31
Q

Know how the current flows inside X-ray tube

A

Anode ➡️ cathode

32
Q

Know what the symbol means and stands for

A

Solid state rectifiers/diode

Current flow is with the direction of the arrow and electron flow is against the arrow

33
Q

Define half-wave rectification

A

When only two rectifiers are used and only one half of the AC cycle flows through the xray and the other half is suppressed

34
Q

Define full-wave rectification

A

When four rectifiers are used and both halves of the AC are used.
•By using four rectifiers & arranging them in specific way, both halves of the AC are used
•Resulting waveform is illustrated
•In effect, we “invert” the negative half of the cycle, thereby making use of the entire cycle

35
Q

Define ripple

A

Measures the amount of variation between maximum and minimum voltage

36
Q

Know what filament circuit begins with

A

Rheostat

37
Q

Define milliampere parameter

A

(Tube current) it reflects the rate of flow of electrons passing through the X-ray tube during exposure

38
Q

Be able to describe what happens when you adjust milliamperage on operating console

A

You are adjusting the rheostat and the amount of resistance in the filament circuit and ultimately the amount of current applied to the filament in the X-ray tube.

39
Q

Know the relationship between milliamperage and resistance

A

⚫️inverse

Higher milliamperage lower the resistance

40
Q

Know the goal of the filament circuit

A

Literally boil electrons out of the filament wire

41
Q

What would happen in the filament circuit if the current gets too high

A

The tiny wire will be damaged or destroyed

42
Q

What’s the role of the rheostat in the filament circuit

A

Controls filament temperature and the rate at which electrons are boiled off of the filament

43
Q

What’s the role of the timer in the filament circuit

A

Determines the duration of this process

44
Q

What’s the role of the step down transformer In the filament circuit

A

Used in the filament circuit to increase the current by reducing the voltage that is applied to the filament

45
Q

Know the purpose if the filament circuit

A

To control the degree to duration that the filament is heated, which in turn controls the number of electrons boiled off that will ultimately become the tube current

46
Q

Know how the filaments are represented in the console

A

Large focal spot and small focal spot