2

Question 1

measure the voltage provided to the xray imaging system and adjusts the voltage to precisely 220V

Answer 1

line voltage compensator

Question 2

older models require manual adjustment of the line voltage compensator and incorporates a

Answer 2

line voltage meter

Question 3

adjusts the voltage supplied to specific circuit of the xray machine

Answer 3

autotransformer

Question 4

allow the radtechs to select the voltage and control the amount of voltage that will flow across the xray tube

Answer 4

kVp selectors

Question 5

kVp selector can be a ____

major- increment of __ kVp
minor- increment of __ kVp

Answer 5

major or minor kVp selector

10, 1

Question 6

placed across the output terminals of the autotransformer and actually reads voltage in the primary circuit and not the kVp

Answer 6

kVp meter

Question 7

consists of electronic device whose action is to make or break the high voltage across the tube

Answer 7

timer circuit

Question 8

automatically terminate the exposure after prescribed time, usually 6 s

Answer 8

guard timer

Question 9

4 types of timing circuits

Answer 9

synchronous timer, electronic timer, mAs timer, automatic exposure control

Question 10

make use of synchronous motor

Answer 10

synchronous timer

Question 11

device designed to drive a shaft at precisely 60 revolutions per second based on frequency of the supplied current

Answer 11

synchronous motor

Question 12

minimum exposure time is set at 1/60 seconds and timing intervals increases by multiples thereof, 1/30, 1/20, etc

Answer 12

synchronous timer

Question 13

needs to be reset after each exposure and therefore cannot be used for multiple exposures

Answer 13

synchronous timer

Question 14

uses a rather complex circuitry, most accurate xray exposure timers

Answer 14

electronic timer

Question 15

allows a wide range of time intervals to be selected as small as 1 ms

Answer 15

electronic timer

Question 16

suitable for rapid serial exposure such as required in interventional radiology procedures

Answer 16

electronic timer

Question 17

monitors the product of mA and exposure rime snd terminates exposure when the desired mAs value is attained.

Answer 17

mAs timer

Question 18

designed to provide the highest safe tube current for the shortest exposure time

Answer 18

mAs timer

Question 19

this timer is located on the secondary circuit as it must monitor the actual tube current

Answer 19

mAs timer

Question 20

device that measures the quantity of radiation that reaches the image receptor and automatically terminates the exposure when the image receptor has received the required radiation intensity

Answer 20

automatic exposure control AEC

Question 21

now widely used but it is just an addition to an electronic timer, manual to automatic control of exposure

Answer 21

AEC

Question 22

increases the voltage that will be supplied into the xray tube from hundreds to thousands of volts

Answer 22

step-up transformer

Question 23

monitors the xray tube current. connected to the center of the secondary winding of the step down transformer

Answer 23

mA/s meter

Question 24

converts ac to dc, ensures one direction of flow, cathode to anode

Answer 24

rectifiers

Question 25

diodes used for xray machines are solid state diodes made of

Answer 25

silicon

Question 26

can be half wave rectified or full wave rectified

Answer 26

xray machines

Question 27

used for portable xray machines and dental xray machines

Answer 27

half-wave rectification

Question 28

can be made of 0 (self-rectified), 1 or 2 diodes

Answer 28

half wave rectification

Question 29

half-wave rectification- xray output pulsates, producing ___ or ____ pulses each second

Answer 29

50 or 60

Question 30

inefficient because it waste half of the supply of power

Answer 30

half-wave rectification

Question 31

also requires half of the exposure time

Answer 31

half wave rectification

Question 32

used for most permanent radiographic unit

Answer 32

full wave rectification

Question 33

usually made of 4 diodes

Answer 33

full wave rectification

Question 34

full wave rectification- the pulsed output occurs ___ times each second

Answer 34

120

Question 35

why full wave rectification is more efficient than half way rectified unit?

Answer 35

negative half cycle of the input voltage is converted to positive cycle

Question 36

time of exposure is also cut in half

Answer 36

full wave rectification

Question 37

voltage waveform with positive and negative cycle. Voltage is pulsating and swings from zero to maximum potential

Answer 37

single-phase voltage waveform

Question 38

the negative half cycle of the waveform is suppressed

Answer 38

single phase half wave rectified voltage waveform

Question 39

voltage waveform wherein the negative half cycle is converted to positive cycle by rectifiers. voltage is still pulsating

Answer 39

single phase full wave rectified voltage waveform

Question 40

this voltage waveform is composed of three simultaneous voltage waveforms that are out of step with one another. With three phase voltage waveform, voltage no longer drops to 0

Answer 40

three phase voltage waveform

Question 41

in this voltage waveform,a nearly const high voltage is supplied to the xray tube

Answer 41

three phase six pulse voltage waveform (full wave rectified)

Question 42

additional component is added to further improve the number of pulses in a cycle

Answer 42

three phase 12 pulse voltage waveform

Question 43

in this voltage waveform, the usual frequency (50 or 60 hz) before converting to high voltage. This produces nearly constant potential voltage waveform, improving image quality at lower patient dose.

Answer 43

high frequency voltage waveform (constant potential)

Question 44

part of the high voltage circuit. the circuit is completed once the electrons produced on the filament travel from cathode to anode. However, the reverse is not possible as anode cannot produce electrons.

Answer 44

X-ray tube

Question 45

controls the filaments current that will be supplied to the filament of the xray tube. This current controls the temperature of the filament

Answer 45

The Filament Circuit

Question 46

As filament current increases, the filament becomes hotter, and more electrons are released by thermionic emission

Answer 46

filament circuit

Question 47

as filament current increases

Answer 47

filament becomes hotter and more electrons are released

Question 48

it is measured in amperes (A). Filament operates ar currents between 5 to 7 A

Answer 48

filament circuit

Question 49

filament circuit consists of

Answer 49

mA selector (Rheostat, focal spot selector, step down transformer

Question 50

reduces the voltage supply from the autotransformer by varying the resistance through the circuit

Answer 50

mA selector / Rheostat

Question 51

controlled by the mA selector on the opera console. The higher the mA station, the lower the resistance. The lower the mA station, the higher the resistance

Answer 51

mA selector / rheostat

Question 52

the higher the mA station

Answer 52

the lower the resistance

Question 53

lower the mA station

Answer 53

higher the resistance

Question 54

current of about 0.5 to 1 A is supplied to the primary side of the transformer

Answer 54

mA selector / rheostat

Question 55

selects the filament (small or large) that will be heated, which corresponds to the focal spot size

Answer 55

focal spot selector

Question 56

connected to the primary windings of the step down transformer

Answer 56

focal spot selector

Question 57

decreases the voltage and increases the current that is supplied to heat the filament of the xray tube

Answer 57

step down transformer

Question 58

the primary windings carry a voltage of 150 V at a current of 0.5 to 1 A, and the secondary windings carry a voltage of 12 V at a current of 5 to 8 A

Answer 58

step down transformer