The x-ray beam
1. Which x-ray tube component serves as a source of electrons for x-ray production?
a) Focusing cup
b) Filament
c) Stator
d) Target
Ans. B
2.
Electrons interact with the ______ to produce x-rays and heat.
a) Focusing cup
b) Filament
c) Stator
d) Target
Ans. D
3.
The cloud of electrons that forms before x-ray production is referred to as
______.
a) Thermionic emission
b) Space charge
c) Space charge effect
d) Tube current
Ans. B
4.
The burning or boiling-off of electrons at the cathode is referred to as
______.
a) Thermionic emission
b) Space charge
c) Space charge effect
d) Tube current
Ans. A
5.
Which primary exposure factor influences both the quantity and the quality of
x-ray photons?
a) MA
b) MAs
c) Kvp
d) Exposure time
Ans. C
6.
The unit used to express tube current is ______.
a) MA
b) MAs
c) Kvp
d) S
Ans. A
7.
What percentage of the kinetic energy is converted to heat when moving
electrons strike the anode target?
a) 1%
b) 25%
c) 59%
d) 99%
Ans. D
8.
The intensity of the x-ray beam is greater on the ______.
a) Cathode side of the tube
b) Anode side of the tube
c) Short axis of the beam
d) Long axis of the beam
Ans. A
9.
According to the line-focus principle, as the target angle decreases, the
________.
a) Actual focal spot size decreases
b) Actual focal spot size increases
c) Effective focal spot size decreases
d) Effective focal spot size increases
Ans. C
10.
___________ extends x-ray tube life.
a) Selecting higher tube currents
b) Using small focal spots when possible
c) Producing exposures with a wide range of kvp values
d) Warming up the tube after 2 h of non-use
Ans. D
11.
Which type of target interaction is responsible for most of the x-rays in the
diagnostic beam?
a) Characteristic interaction
b) Thermionic emission
c) Bremsstrahlung interaction
d) None of the above
Ans. C
12.
What value of mas is produced when the radiographer sets a kilovoltage peak of 70
kVp, a milliamperage of 600 mA, and an exposure time of 50 ms?
a) 3.5 mas
b) 30 mas
c) 300 mas
d) 350 mas
Ans. B
13.
Increasing the kvp results in ______.
a) X-rays with higher energy
b) X-rays with lower energy
c) More x-rays
d) A and c e. B and c
Ans. D
14.
Total filtration in the x-ray beam includes ______.
a) Compensating filters
b) Inherent filtration
c) Added filtration
d) B and c
e) All of the above
Ans. D
15.
How many heat units result from an exposure made on a single-phase x-ray unit
using a beam current of 400 ma, an exposure time of 0.2 s, and a kilovoltage
peak of 70 kVp?
a) 5600 hu
b) 7560 hu
c) 7896 hu
d) 8120 hu
Ans. A