chapter 6 (The x ray imaging system )

Question 1

A falling load generator allow for a _________ exposure when compared to a fixed mA.

Answer 1

Shorter

Question 2

A________ transformer is used to increase filament current.

Answer 2

Step- down

Question 3

The unrectified voltage waveform _________before the x ray tube.

Answer 3

has both a positive and negative component.

Question 4

which of the following is a disadvantage of a three phase power compared to a single phase?

Answer 4

Higher costs

Question 5

what material are most patient tables made of ?

Answer 5

Carbon fiber

Question 6

Assuming the same maximum kvp and mAs, the power rating of a single phase system is ______ a three phase system.

Answer 6

less than

Question 7

_________ is a voltage waveform that results in thousands of pulses per second after rectification.

Answer 7

High frequency

Question 8

A three phase waveform has _______ ripple.

Answer 8

13%

Question 9

The x-ray tube current is monitored on the __________.

Answer 9

secondary side of the high voltage transformer.

Question 10

with half wave rectification current flows through the x ray tube during the ________part of the cycle.

Answer 10

positive

Question 11

The difference in waveform between primary and secondary sides of the high voltage transformer is _______

Answer 11

Amplitude

Question 12

Full wave rectifiers use both the positive and negative parts of a wave, which __________.

Answer 12

cuts the exposure time in half

Question 13

The_____ timer operates based on a wound spring.

Answer 13

mechanical

Question 14

The autotransformer has_____ coil(s).

Answer 14

one

Question 15

The most accurate type of timer is the ________ timer.

Answer 15

Electronic

Question 16

which statement is true about machines using a half-wave rectified voltage waveform?

Answer 16

All of the above.
- they require twice the exposure time of full- wave rectified circuits.
- Electrons are accelerated from the cathode to anode of the x ray tube in the positive voltage cycle.
- they do not operate in the negative portion of the waveform
- they have a 100% ripple.

Question 17

________ require a back up timer.

Answer 17

AEC timers.

Question 18

Variations in power distribution to the x ray machine are corrected by the _________.

Answer 18

line voltage compensator.

Question 19

The three main parts of the x ray imaging system are the ________, ________ and ________.

Answer 19

• X- ray tube
• operating console
• high voltage generator.

Question 20

As the number of pulses increase over a fixed time, the ripple______.

Answer 20

decreases.

Question 21

When high voltage is on the cathode side of a vacuum tube rectifier, _______.

Answer 21

there is NO current flow

Question 22

The automatic exposure control (AEC) terminates the exposure when ________.

Answer 22

sufficient radiation reaches the image receptor.

Question 23

The generator that produces the least penetrating x rays and results in a highest radiation dose to the patient for the same kvp is the _______.

Answer 23

single phase half wave rectified.

Question 24

The voltage waveform supplied to the primary side of the high voltage transformer is________.

Answer 24

unrectified

Question 25

The first component to receive power in the x ray circuit is the ________.

Answer 25

autotransformer.

Question 26

The rectification process converts ________.

Answer 26

AC to DC

Question 27

A high frequency waveform has _____ ripple.

Answer 27

1%

Question 28

What is the industry standard formula for calculating high voltage generator power rating?

Answer 28

Power= f x max mA (@100kvp and 100 ms) x 100 kvp.

Question 29

An autotransformer has a primary current of 800 mA. If there are 350 turns on the primary side and 460 turns on the secondary side, what is true about the transformer?

Answer 29

The turns ratio is greater than 1.

Question 30

In modern imaging systems, the components for rectification are_______.

Answer 30

solid state semiconductors.

Question 31

Low voltage ripple results in ________ radiation quantity and quality.

Answer 31

increased.

Question 32

The x ray machine console allows you to control _____,_______ and _____.

Answer 32

- kV - mAs - focal spot size

Question 33

The high voltage generator contains the _______ the ______ and the _______.

Answer 33

- high voltage transformer - filament transformer - rectifiers

Question 34

_______ is a voltage waveform that results in 360 pulses per second after rectification.

Answer 34

Three phase.

Question 35

What is the main goal for a mAs timer?

Answer 35

minimize the effects of patient motion.

Question 36

What type of time can be used for rapid serial exposure and is very reproducible?

Answer 36

Electronic timer.

Question 37

Voltage across the x ray tube is most constant with ______

Answer 37

High frequency generators.

Question 38

_____ is measured by mA and _____is measured by mAs.

Answer 38

Current , charge.

Question 39

the x ray generator with the lowest power rating is the _________imaging system.

Answer 39

single-phase.

Question 40

The high voltage transformer has____

Answer 40

a turns ratio greater than one.

Question 41

which of the following results in best utilization of the voltage waveform?

Answer 41

full wave rectified.

Question 42

A step - down transformer is located in the _____ circuit.

Answer 42

filament

Question 43

semiconductor reciters have two material types a p- type material with excess _____ and an n- type material with excess______.

Answer 43

holes, electrons.

Question 44

The filament transformer ______.

Answer 44

increases the current.

Question 45

The timer that operates based on a shaft rotating at a set speed is the _______ timer.

Answer 45

synchronous.

Question 46

Voltage is______ related to the turns ratio.

Answer 46

directly

Question 47

In full wave rectification, the wave applied across the x ray tube is always_______.

Answer 47

positive.

Question 48

All the console controls are on the ______ side of the high voltage transformer and the ______side of the filament transformer

Answer 48

primary, primary

Question 49

A single phase waveform has ____ripple.

Answer 49

100%

Question 50

Ionization chambers are ________in AEC systems.

Answer 50

between the patient and the image receptor.

Question 51

the kvp meter is located ________.

Answer 51

on the primary side of the high voltage transformer.

Question 52

The _____ circuit provides electrons for the x ray tube current

Answer 52

filament.

Question 53

In a semiconductor rectifier, when higher potential is placed on the P -side______.

Answer 53

there is Current flow through the diode.

Question 54

Power to the primary side of the high voltage transformer comes from the _____.

Answer 54

secondary side of the autotransformer.

Question 55

The inverter is the device that "chops" the waves into smaller shorter waves in a _______.

Answer 55

high frequency generator.

Question 56

Current is _____ related to the turns ratio.

Answer 56

inversely