Physics Final Review Flashcards


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1

Cooling Charts are available for the

Tube Housing and Anode

Both A and B are correct

2

Most x-ray tube target angles range between

7-18 degrees

3

Of all the energy involved in x-ray production, 99% is converted to

Heat

4

The melting point of tungsten is

3400 degrees C

5

Which of the following occurs first during x-ray production

voltage level is adjusted at autotransformer

6

X-ray tubes with a stationary anode design may be found today

in old tubes designs and dental x-ray units or those that require very small exposure techniques.

7

The positive end of the x-ray tube is the

anode

8

Electrons from the cathode that do not produce x-rays will

turn into heat?

9

To keep the electrons together, the focusing cup

forces electrons together with its strong negative charge

10

The electrons in the tube current travel

half the speed of light

11

The protective tube housing helps to

all of these are correct

12

The filament is primarily made of

tungsten

13

The portion of the induction motor that is outside the tube enclosure is the

stator

14

With a rotating anode, the focal spot becomes a focal

track

15

Which of the following occurs last during x-ray production

The electrons flow from cathode to anode, it is a continuation of the flow of electricity through the x-ray circuit

16

Which of the following practices extend the tube life

all of these are correct

17

The primary advantage of a rotating anode is that it allows

greater heat capacity at the anode

18

The target window is usually approximately

5cm squared

19

Molybdenum is found in the ________ of the rotating anode

both A and B are correct

20

The cloud of electrons produced through thermionic emission is more accurately called a(n)

space charge

21

Heat from x-ray production is removed through conduction by the heat traveling from

heat materials

22

The negative end of the x-ray tube is the

cathode

23

An x-ray tube with two filaments is called a

dual-focus tube

24

The advantages to using a larger actual focal spot is

heat dissipation, the smaller the stream the greater the heat generated in a small area.

25

Pitting of the anode is the result of

extended use

26

To allow x-rays to leave the tube, the glass or metal enclosure in the area of the target window is

made thinner

27

Glass enclosures are typically made of borosilicate glass (Pyrex) because

it is very heat-resistent

28

Based on the anode heel effect, an image taken at 40 inches SID may demonstrate

decreased exposure toward the anode end of the beam

29

The focusing cup is able to keep the electrons together because

opposites attract

30

Tube rating charts

all of these are correct

31

The size of the actual focal spot depends on

the size of the cathode filament being used

32

The induction motor turns the rotor of a specialty tube _____ revolution per minute

10,000

33

An issue with using glass envelopes is that they

cause arcing and damage, vaporized tungsten from the filament deposits on the inside of the glass.

34

The space charge effect describes

self-limiting factor, large potential difference to give kinetic energy to the filament electrons, a vehicle on which kinetic energy can ride, and a place for interaction

35

The rotating anode design uses a disc whose core is made of

molybdenum

36

Molybdenum

great at conducting heat, strong and lightweight

37

One of the reasons the molybdenum is used in rotating anodes is because it is

low thermal conductivity, slows migration of heat into the rotor bearings minimizing heat damage, lightweight and strong, easy to rotate

38

After lengthy exposures, the x-ray tube on a mobile fluroscopic unit may

be very hot

39

Which of the following occurs first during x-ray production

The voltage from the autotransformer passes to the step-up transformer.

40

The filaments are part of the

filament circuit

41

Heat from x-ray production is removed through convection by the heat traveling from

the tube to the room by cooling fans

42

The two types of anode designs are stationary and

rotating

43

If the anode angle becomes too small, which of the following may result

all of these are correct

44

Arcing

is a problem associated with glass envelopes

45

Copper can be found _____ of the rotating anode

in the shaft

46

The cathode includes the

both B and C are correct

47

Part of the useful x-ray beam gets absorbed in the anode when

the anode angle is too small

48

The stationary anode includes an are of tungsten embedded in

copper rod

49

For the covering of the rotating anode disc, _______ may be added to tungsten to increase thermal capacity

Rhenium

50

The formula kvp x mA x s x c is used to calculate

heat units

51

The area of the envelope where x-rays should exit the tube is the

window

52

The anode serves as a(n)

all of these are correct

53

The best situation is to have a _____ actual focal spot and a _______ effective focal spot.

large; small

54

Tungsten is used to coat the anode disc because it

has a high atomic number

55

The cathode

all of these are correct

56

The tube rating chart plots mAs, kvp, and

exposure time

57

The anode includes the

both A and B are correct

58

The primary purpose of the glass or metal exposure is to

maintain a vacuum

59

The advantage to using a small effective focal spot is

the image is sharper

60

When the exposure switch at the operating console is first depressed

Some of the electricity is diverted to the induction motor of the x-ray tube to bring the rotor up to speed. Induction motor turns the anode at 3400 rpm

61

The stationary anode includes an area of _______ embedded in a copper rod

tungsten

62

The most common x-ray tube target angle is

12 degrees

63

Tungsten is used to coat the anode disc because it

conducts heat well

64

The rotor is made of

iron core (iron bars embedded in the copper shaft)

65

Which of the following practices extend tube life

press the prep and exposure switches at almost the same time

66

The motor that turns the anode operates through

mutual induction

67

The focusing cup is made of

nickel

68

The effective focal spot is the

size of origin of the x-ray beam as seen from below the tube

69

By regulation, x-ray tube leakage radiation can be no more than

100 mR per hour

70

The primary disadvantage to the stationary anode is that it

heats up too quickly during x-ray production

71

The focusing cup is part of the

secondary circuit

72

The atomic number of tungsten is

74

73

Heat from x-ray production is removed through radiation by the heat traveling from

the tube to the oil bath

74

How many heat units are produced with five consecutive exposures using a three-phase, 12-pulse x-ray unit, 85 kvp, and 20 mAs?

11,985 HU

75

Of all the energy involved in x-ray production, _______ is converted to x-ray energy.

1%

76

Tungsten is used to coat the anode disc because it

has a high melting point

77

The protective tube housing is lined with

metal structure that serves as an electrical insulator and thermal cushion for the tube itself; lead lined

78

There is a small amount of _____ added to the filament to increase thermionic emission.

thorium

79

The purpose of the focusing cup is to

keep the electrons together

80

In terms of the x-ray tube, envelope is another name for the

glass or metal enclosure

81

The induction motor turns the rotor of a standard x-ray tube ______ revolutions per minute

3400

82

Thermionic emission is

heating the filament until electrons are boiled off

83

Excessive heat may be transferred to the rotor bearings, resulting in

the anode rotating unevenly

84

The rotor is found

inside the envelope

85

The ______ is used to calculate the length of time needed between exposures so that the tube's heat loading capacity is not exceeded

cooling chart

86

The relationship between the actual focal spot size, effective focal spot size, and anode target angle is called

the line-focus principle

87

The smaller the anode angle

the smaller the effective focal spot

88

Copper is used in the rotating anode because

it is an excellent conductor

89

With a rotating anode, the focal spot becomes a focal

track

90

In terms of the x-ray tube, envelope is another name for the

glass or metal enclosure

91

The portion of the induction motor that is outside the tube enclosure is the

stator

92

Using very long exposures can lead to tube damage or failure:

True or False

True

93

By regulation, x-ray tube leakage radiation can be no more than:

100 mR per hour

94

The anode includes the

both A and B are correct

95

An x-ray tube with two filaments is called a

dual-focus tube

96

To take advantage of the anode heel effect, the thinner part of the anatomy being imaged should be placed under the cathode end of the tube.

True or False

False

97

Which of the following practices extend tube life?

Press the prep and exposure switches at almost the same time

98

The stator is made up of electromagnets.

True or False

True

99

How many heat units are produced with five consecutive exposures using a three-phase, 12-pulse x-ray unit; 85 kVp, and 20 mAs?

11,985

100

The cathode

all of these are correct

101

To take advantage of the anode heel effect, the thicker part of the anatomy being imaged should be placed under the anode end of the tube.

True or False

False

102

The primary purpose of the glass or metal enclosure is to

maintain a vacuum

103

The rotating anode design uses a disc whose core is made of

molybdenum

104

The primary disadvantage to the stationary anode is that it

heats up too quickly during x-ray production

105

Based on the anode heel effect, an image taken at 40 inches SID may demonstrate

decreased exposure toward the anode end of the beam

106

The tube rating chart plots mA, kVp, and

exposure time

107

The cloud of electrons produced through thermionic emission is more accurately called a

space charge

108

The motor that turns the anode operates through

mutual induction

109

Heat from x-ray production is removed through convection by the heat traveling from

cooling fans

110

The two types of anode designs are stationary and

rotating

111

The effective focal spot is smaller than the actual focal spot because the face of the anode is angled.

True or False

True

112

To allow x-rays to leave the tube, the glass or metal enclosure in the are of the target window is

made thinner

113

The filaments are part of the

filament circuit

114

For the covering of the rotating anode disc, ______ may be added to tungsten to increase thermal capacity.

rhenium

115

The target window is usually approximately

5 cm squared

116

The rotor is supplied with electric current through the x-ray circuit.

True or False

False

117

Which of the following occurs first during x-ray production?

Voltage level is adjusted at autotransformer

118

How many heat units are produced with an exposure using a single phase x-ray unit, 75 kVp, and 50 mAs?

3750 HU

119

Prepping the rotor but not making an exposure on a regular basis is unrelated to tube damage or failure.

True or False

False

120

When electrons strike the anode target, they all produce x-rays.

True or False

False

121

Molybdenum is found in the ________ of the rotating anode.

both A and B are correct

122

Arcing:

is a problem associated with glass envelopes

123

The ________ is used to calculate the length of time needed between exposures so that the tube's heat loading capacity is not exceeded.

cooling chart

124

The most common x-ray tube target angle is:

12 degrees

125

An issue with using glass envelopes is that they:

allow vaporized tungsten to coat the inside of the glass

126

The stationary anode includes an area of _______ embedded in a copper rod

tungsten (button)

127

The oil surrounding the x-ray tube serves only to provide electrical insulation.

True of False

False

128

Copper is used in the rotating anode because

it is an excellent conductor

129

The positive end of the x-ray tube is the

anode

130

Many newer x-ray units do not need the radiographer to go through a warm-up procedure.

True or False

True

131

The purpose of the focusing cup is to

keep electrons together