RADIATION SAFETY TEST QUESTIONS
AND ANSWERS
Natural background radiation represents what percentage of humans' radiation
exposure?
A. 21%
B. 50%
C. 82%
D. 5% - Answer-B
The greatest source of natural background radiation exposure is:
A. cosmic rays
B. radioactive materials
C. the body itself
D. radon gas - Answer-D
Cosmic radiation:
A. is present only in space
B. is a source of exposure only to persons who lie in the sun
C. is of concern only to space travelers
D. is a part of natural background exposure - Answer-D
Radon gas:
A. presents a danger when undetected
B. is present in doses proportional to other sources
C. is entirely human-made
D. is the source of 100% of annual background dose - Answer-A
X-rays and gamma rays used in diagnostic imaging are:
A. not of concern because the beam is filtered
B. part of the natural background dose
C. part of an artificial background radiation dose
D. an insignificant dose to the general population because they are used safely -
Answer-C
A feature of fluoroscopic x-ray machines that automatically adjusts kVp and mA so as to
maintain image brightness for necessary image quality is called:
A. automatic imaging
,B. automatic brightness control (ABC)
C. automatic image processing
D. constant exposure output - Answer-B
What term best describes the approximate skin dose where the x-ray beam is entering
the patient?
A. effective dose
B. nonoccupational dose
C. in-air exposure
D. air kerma - Answer-D
Sievert is calculated by multiplying gray by
A. W(R)
B. W(a)
C. W(t)
D. mAs - Answer-A
The total of air kerma over the exposed area of the patient is called:
A. dose area product
B. mean marrow dose
C. genetically significant dose
D. total patient dose - Answer-A
Which of the following is also known as coherent scattering?
A. photoelectric interaction
B. compton interaction
C. classical scatter
D. pair production - Answer-C
Which of the following photon-tissue interactions does not occur in diagnostic
radiography?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-D
Which of the following is responsible for creating the conditions for contrast on the
image?
A. photoelectric interaction
B. compton interaction
, B. coherent scatter
D. pair production - Answer-A
Which of the following produces scatter radiation that exits the patient and may fog the
image?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-B
Which of the following produces scatter as a result of vibration of orbital electrons?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-C
Which of the following results in total absorption of an incident x-ray photons?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-A
Which of the following is the only photon-tissue interaction that does not results in
ionization?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-C
Which of the following involves interactions between an incident photon and an atomic
nucleus?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-D
Which of the following photon-tissue interactions primarily involves K-shell electrons?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
AND ANSWERS
Natural background radiation represents what percentage of humans' radiation
exposure?
A. 21%
B. 50%
C. 82%
D. 5% - Answer-B
The greatest source of natural background radiation exposure is:
A. cosmic rays
B. radioactive materials
C. the body itself
D. radon gas - Answer-D
Cosmic radiation:
A. is present only in space
B. is a source of exposure only to persons who lie in the sun
C. is of concern only to space travelers
D. is a part of natural background exposure - Answer-D
Radon gas:
A. presents a danger when undetected
B. is present in doses proportional to other sources
C. is entirely human-made
D. is the source of 100% of annual background dose - Answer-A
X-rays and gamma rays used in diagnostic imaging are:
A. not of concern because the beam is filtered
B. part of the natural background dose
C. part of an artificial background radiation dose
D. an insignificant dose to the general population because they are used safely -
Answer-C
A feature of fluoroscopic x-ray machines that automatically adjusts kVp and mA so as to
maintain image brightness for necessary image quality is called:
A. automatic imaging
,B. automatic brightness control (ABC)
C. automatic image processing
D. constant exposure output - Answer-B
What term best describes the approximate skin dose where the x-ray beam is entering
the patient?
A. effective dose
B. nonoccupational dose
C. in-air exposure
D. air kerma - Answer-D
Sievert is calculated by multiplying gray by
A. W(R)
B. W(a)
C. W(t)
D. mAs - Answer-A
The total of air kerma over the exposed area of the patient is called:
A. dose area product
B. mean marrow dose
C. genetically significant dose
D. total patient dose - Answer-A
Which of the following is also known as coherent scattering?
A. photoelectric interaction
B. compton interaction
C. classical scatter
D. pair production - Answer-C
Which of the following photon-tissue interactions does not occur in diagnostic
radiography?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-D
Which of the following is responsible for creating the conditions for contrast on the
image?
A. photoelectric interaction
B. compton interaction
, B. coherent scatter
D. pair production - Answer-A
Which of the following produces scatter radiation that exits the patient and may fog the
image?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-B
Which of the following produces scatter as a result of vibration of orbital electrons?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-C
Which of the following results in total absorption of an incident x-ray photons?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-A
Which of the following is the only photon-tissue interaction that does not results in
ionization?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-C
Which of the following involves interactions between an incident photon and an atomic
nucleus?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
D. pair production - Answer-D
Which of the following photon-tissue interactions primarily involves K-shell electrons?
A. photoelectric interaction
B. compton interaction
B. coherent scatter
