Deck 5: X-Ray Production

Question 1

Below what kVp level is characteristic radiation no longer produced?

A) 40 kVp
B) 50 kVp
C) 70 kVp
D) 100 kVp

Answer 1

70 kVp

Question 2

What percentage of the total energy applied to an x-ray tube target is converted into x-rays?

A) 1%
B) 50%
C) 75%
D) 99%

Answer 2

1%

Question 3

The greatest portion of the x-ray beam is made up of:

A) characteristic-produced radiation.
B) bremsstrahlung-produced radiation.
C) low-energy electrons.
D) high-energy electrons.

Answer 3

bremsstrahlung-produced radiation.

Question 4

More than 99% of the energy applied to an x-ray tube is converted into:

A) bremsstrahlung radiation.
B) characteristic radiation.
C) secondary radiation.
D) heat.

Question 5

The "electron cloud" that surrounds the hot cathode is referred to as a:

A) focusing cup.
B) photon.
C) filament.
D) space charge.

Question 6

What type of radiation is produced when an incoming electron interacts with the K-shell electron in the tungsten atom?

A) Characteristic radiation
B) Scatter radiation
C) Bremsstrahlung radiation
D) Thermionic emission

Question 7

What type of radiation is produced in the anode by the sudden slowing and directional change of an incoming electron?

A) Characteristic radiation
B) Scatter radiation
C) Bremsstrahlung radiation
D) Thermionic emission

Question 8

The cathode end of the x-ray tube is ______ charged.

A) positively
B) negatively
C) neutrally
D) radioactively

Question 9

Which of the following are the types of radiation produced in the anode?

A) Thermionic emission and heat
B) Electromagnetic and thermal
C) Characteristic and bremsstrahlung
D) Remnant and scatter

Question 10

Most x-ray tubes in use today have a standard rotation speed of ______ rpm.

A) 1,500
B) 2,000
C) 3,600
D) 10,000

Question 11

What are the four essential elements required for x-ray production?

A) A target, a vacuum, an electron source, and a high potential difference
B) A target, a source of electrons, an inert gas environment, and a high potential difference
C) A source of electrons, a magnetic field, a resistance-free path, and a target
D) A source of electrons, an electric field, a circuit, and a target

Question 12

The filament of an x-ray tube is made of:

A) glass.
B) a coil of copper wire.
C) a coil of tungsten wire.
D) a fluorescent tube.

Question 13

The anode,or target,of the x-ray tube is ______ charged.

A) positively
B) negatively
C) neutrally
D) radioactively

Question 14

When tungsten atoms are heated,their outermost electrons are moved out of the atom in space. This principle is called:

A) electromagnetic induction.
B) variable resistance.
C) quantum theory.
D) thermionic emission.

Question 15

The x-ray tube inside the protective housing is made of:

A) lead.
B) steel.
C) aluminum.
D) Pyrex glass.

Question 16

What is required to move the electron stream rapidly across the x-ray tube?

A) Magnetic field
B) High potential difference
C) Focusing cups
D) Copper mass in the target

Question 17

Free electrons at the cathode that are used for x-ray production come from the:

A) filament.
B) target.
C) anode.
D) kilovoltage.

Question 18

What is the principal advantage of a high-speed rotating anode?

A) More efficient production of x-rays
B) Increased amount of characteristic radiation produced
C) Increased amount of bremsstrahlung radiation produced
D) More efficient heat dissipation

Question 19

The target of the x-ray tube is made of:

A) tungsten.
B) glass.
C) stainless steel.
D) fluorescent phosphors.

Question 20

A device for removing long wavelength radiation from the primary x-ray beam is a:

A) collimator.
B) rheostat.
C) rectifier.
D) filter.

Question 21

An x-ray exposure is made using the following factors: 400 mA,0.02 sec,80 kVp,40 inches SID,and the large focal spot. What is the mAs for this exposure technique?

A) 0.08 mAs
B) 0.8 mAs
C) 8 mAs
D) 80 mAs

Question 22

The purpose of rotating the x-ray tube target is to:

A) create a space charge.
B) speed up the electrons in the electron stream.
C) remove long wavelength photons from the x-ray beam.
D) increase the heat capacity of the anode.

Question 23

Which of the following occurs when the mA is doubled?
1) The number of x-ray photons decreases by 50%.
2) Radiographic density increases.
3) There are twice as many photons in the x-ray beam.

A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2, and 3

Question 24

A smaller effective focal spot produces:

A) greater tube heat capacity.
B) lower patient dose.
C) more characteristic radiation.
D) greater image sharpness.

Question 25

The mAs used for an exposure determines the:

A) wavelength of the resulting x-ray beam.
B) quantity of radiation in the exposure.
C) rate at which x-rays are produced.
D) voltage across the x-ray tube.

Question 26

What is the primary advantage of x-ray beam filtration?

A) Increases the heat capacity of the x-ray tube
B) Improves image quality
C) Lowers patient dose
D) Provides a more even density along the length of a part

Question 27

When exposure time is very short,the time is usually measured in:

A) milliseconds.
B) deciseconds.
C) kiloelectron volts.
D) angstroms.

Question 28

Which of the following statements is true regarding the characteristics of tungsten?

A) Tungsten has a low melting point.
B) Tungsten is a very soft metal.
C) Tungsten is a very unstable element.
D) Tungsten has a high melting point.

Question 29

The x-ray beam is made up of many different energy x-rays. This beam is referred to as:

A) attenuated.
B) heterogenous.
C) ionized.
D) electromagnetic.

Question 30

X-ray equipment capable of producing 70 kVp or more must have how much equivalent aluminum filtration?

A) 0.5 mm Al equivalent
B) 1.0 mm Al equivalent
C) 2.5 mm Al equivalent
D) 3.5 mm Al equivalent

Question 31

A larger actual focal spot produces:

A) greater image sharpness.
B) greater tube heat capacity.
C) lower patient dose.
D) more characteristic radiation.

Question 32

Filtration ______ the average wavelength of the x-ray beam.

A) increases
B) decreases
C) does not affect
D) has no relation to

Question 33

The anode heel effect is a phenomenon of x-ray production that results in:

A) dissipation of anode heat.
B) filtration of long wavelengths from the x-ray beam.
C) uneven distribution of radiation within the field.
D) the production of characteristic radiation.

Question 34

A steeper target angle provides:

A) more heat capacity.
B) lower patient dose.
C) less anode heel effect.
D) smaller effective focal spot.

Question 35

The degree of angulation of the x-ray tube target will determine the:

A) effective focal spot.
B) speed of anode rotation.
C) number of photons in the x-ray beam.
D) heat capacity of the anode.

Question 36

Which of the following can be found on a dual-focus x-ray tube?
1) Two filaments
2) Two focal spot sizes
3) Two anodes

A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2, and 3

Question 37

The penetrating power of the x-ray beam is controlled by varying the:

A) anode angle.
B) anode speed.
C) milliamperage.
D) kilovoltage.

Question 38

If an exposure time is measured as 35 milliseconds,what is the exposure time in seconds?

A) 0.350 seconds
B) 350 seconds
C) 0.035 seconds
D) 3.5 seconds

Question 39

The current across the x-ray tube is measured in units of:

A) milliamperes.
B) kilovolts.
C) roentgens.
D) ohms.

Question 40

Taking into account the anode heel effect when making a recumbent AP radiograph of the femur (thigh bone)on a 14 × 17-inch IR at 40 inches SID,the patient should be placed so that the:

A) head is toward the anode end of the tube.
B) head is toward the cathode end of the tube.
C) position is convenient; the anode heel effect is not significant in this case.

Question 41

The precise area on the target where the x-rays strike is called the:

A) focal track.
B) focal spot.
C) actual focal spot.
D) effective focal spot.

Question 42

Where is the electromagnetic induction motor used in the x-ray machine?

A) Rotate the anode
B) Move the tabletop
C) Move the grid
D) Send electrons to the filament

Question 43

Which of the following would be considered added filtration in the x-ray tube?

A) Oil
B) Pyrex glass
C) Aluminum
D) Tungsten

Question 44

The density in the radiographic image is primarily controlled by the:

A) mA.
B) mAs.
C) kVp.
D) SID.

Question 45

Which of the following would be considered inherent filtration?
1) Oil
2) Mirror
3) Pyrex glass

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 3

Question 46

The contrast in the radiographic image is controlled by the:

A) ma.
B) mAs.
C) kVp.
D) exposure time.

Question 47

The difference in x-ray intensity (or volume of x-rays)between the anode and the cathode side of the x-ray beam is:

A) 45%.
B) 60%.
C) 75%.
D) 80%.