,
,
,
, c. x-rays.
d. A and B.
e. A and C.
ANS: E
The electrical energy applied to the x-ray tube will be transformed into heat (primarily) and
x-rays.
REF: p.5
19. The Greek symbol lambda () represents the x-ray’s:
a. wavelength.
b. speed.
c. frequency.
d. quantity.
ANS: A
Lambda () is the Greek symbol that represents wavelength.
REF: p.6
20. An angstrom (Å) is equal to:
a. 101 meter
b. 1010 meter
c. 101 foot
d. 1010 foot
ANS: B
One angstrom is equal to 1010 meter.
REF: p.6
21. X-rays used in radiography have wavelengths ranging from 0.1 to:
a. 0.01 Å.
b. 1 Å.
c. 10 Å.
d. 100 Å.
ANS: B
X-rays used in radiography have wavelengths ranging from 0.1 to 1 Å.
REF: p.6
22. X-rays used in radiography have wavelengths ranging from 3 1019 to:
a. 3 108 Hz.
b. 3 1010 Hz.
c. 3 1010 Hz.
d. 3 1018 Hz.
ANS: D
X-rays used in radiography have wavelengths ranging from 3 1019 to 3 1018 Hz.
, REF: p.6
23. In the formula c = v, c represents:
a. frequency.
b. the speed of light.
c. wavelength.
d. kinetic energy.
ANS: B
In this formula, c represents the speed of light.
REF: p.6
24. In the formula c = v, v represents:
a. frequency.
b. the speed of light.
c. wavelength.
d. kinetic energy.
ANS: A
In this formula, v represents frequency.
REF: p.6
25. The energy of an individual x-ray photon is measured in:
a. frequency.
b. wavelength.
c. kilovolts peak (kVp).
d. electron volts (eV).
ANS: D
X-ray photon energy is measured in electron volts (eV).
REF: p.7
26. An x-ray beam that has photons with many different energies is:
a. homogenous.
b. monoenergetic.
c. heterogeneous.
d. never found.
ANS: C
A heterogeneous x-ray beam consists of photons with many different energies.
REF: p.8
27. X-rays can:
a. penetrate the human body.
b. be absorbed in the human body.
c. change direction in the human body.
d. A and B only.
e. all of the above.
, ANS: E
X-rays can penetrate, be absorbed in, or change direction (due to scattering) in the human
body.
REF: p.9
28. In conjunction with ALARA, which of the following cardinal principles help to minimize
radiation exposure?
I. Time—Increase time exposed to ionizing radiation
II. Time—Decrease time exposed to ionizing radiation
III. Distance—Increase distance from ionizing radiation
IV. Distance—Decrease distance from ionizing radiation
V. Shielding—Maximize use of shielding from ionizing radiation
a. I, III, and V
b. I, IV, and V
c. II, III, and V
d. II, IV, and V
ANS: C
The cardinal principles include decreasing time exposed to ionizing radiation, increasing
distance from ionizing radiation, and maximizing use of shielding from ionizing radiation.
REF: p.9
TRUE/FALSE
1. X-rays are invisible.
ANS: T
A characteristic of x-rays is that they are invisible.
REF: p.9
2. X-rays carry a negative charge that causes ionization.
ANS: F
X-rays are electrically neutral.
REF: p.9
3. X-ray photons travel at the speed of light in a vacuum.
ANS: T
In a vacuum, x-rays will travel at the speed of light.
REF: p.9
4. X-ray photons are capable of traveling around corners.
ANS: F
X-rays travel in straight lines, so they are unable to travel around corners.
, REF: p.9
5. Chemical changes may occur as a result of exposure to ionizing radiation.
ANS: T
Chemical changes, such as in radiographic or photographic film, occur as a result of exposure
to ionizing radiation.
REF: p.9
6. X-rays will change direction in the presence of a strong magnetic field.
ANS: F
X-rays do not respond to a magnetic field.
REF: p.8
7. X-rays produce a slight tingling sensation when they enter the body.
ANS: F
X-rays cannot be felt.
REF: p.8
8. X-rays cannot be focused with a lens.
ANS: T
Unlike visible light, it is not possible to focus x-rays with a lens.
REF: p.9
9. X-rays are able to interact with certain materials and produce light energy.
ANS: T
Certain materials will fluoresce, or produce light energy, when stimulated by x-rays.
REF: p.9
10. It is impossible for x-rays to interact with matter and produce secondary radiation.
ANS: F
Secondary radiation is often produced as a result of x-rays interacting with matter.
REF: p.9
11. X-rays can produce ionization of atoms making up cells, causing damage.
ANS: T
A major reason that unnecessary exposure must be avoided is that x-rays can ionize atoms and
cause damage.
, REF: p.9
12. Since Roentgen’s discovery in the late nineteenth century, we have learned an enormous
amount about the properties of x-rays.
ANS: F
Roentgen’s original work on the characteristics of x-rays was so thorough that very little has
been learned about their properties since.
REF: p.12
13. It is the radiographer’s responsibility to minimize the radiation dose to the patient, to
themselves, and to others in accordance with the As Low As Reasonably Achievable
(ALARA) principle.
ANS: T
It is the radiographer’s responsibility to minimize the radiation dose to the patient, to
themselves, and to others in accordance with the As Low As Reasonably Achievable
(ALARA) principle.
REF: p.12
14. Screening for pregnancy is an important task for minimizing unnecessary exposure to a
developing fetus.
ANS: T
Screening for pregnancy is an important task for minimizing unnecessary exposure to a
developing fetus.
REF: p.12