Questions and Answers Latest Update
1. Biologic material irradiated under hypoxic conditions
is
(A) more sensitive than when irradiated under
oxygenated conditions
(B) less sensitive than when irradiated under
anoxic conditions
(C) less sensitive than when irradiated under
oxygenated conditions
(D) unaffected by the presence or absence o
oxygen - Answer-(C) less sensitive than when irradiated under
oxygenated conditions
2. According to the National Council on Radiation
Protection and Measurements (NCRP), the monthly
gestational dose-equivalent limit or embryo/ fetus
of a pregnant radiographer is
(A) 0.1 mSv
(B) 0.5 mSv
(C) 1.0 mSv
(D) 5.0 mSv - Answer-(B) 0.5 mSv
3. A time of 1.5 minutes is required for a particular
fluoroscopic examination, whose exposure rate is
275 mR/h. What is the approximate radiation
exposure for the radiologic staff present in the
fluoroscopy room during the examination?
(A) 183 mR
(B) 68.7 mR
(C) 18.33 mR
(D) 6.87 mR - Answer-(D) 6.87 mR
4. Stochastic/probabilistic effects of radiation are
those that
1. have a threshold
,2. may be described as "all-or-nothing" effects
3. are late effects
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3 - Answer-C) 2 and 3 only
5. What percentage of public exposure to ionizing
radiation is from medical sources?
(A) 5%
(B) 10%
(C) 25%
(D) 50% - Answer-(D) 50%
6. Which of the following cell types has the greatest
radiosensitivity in the adult human?
(A) Nerve cells
(B) Muscle cells
(C) Spermatids
(D) Lymphocytes - Answer-(D) Lymphocytes
7. Guidelines for the use fo protective shielding state
that gonadal shielding should be used
1. if the patient has reasonable reproductive
potential
2. when the gonads are within 5 cm of the
collimated field
3. when tight collimation is not possible
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 2 and 3 only - Answer-(B) 1 and 2 only
8. The interaction between ionizing radiation and the
target molecule that is most likely to occur is the
(A) direct effect
(B) indirect effect
(C) target effect
,(D) random effect - Answer-B) indirect effect
9. Sources o natural background radiation include
1. radon
2. internal sources
3. thoron
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3 - Answer-(D) 1, 2, and 3
10. The unit used to express kinetic energy released in
matter is the
(A) erg
(B) gray
(C) kerma
(D) rad - Answer-(C) kerma
11. Which acute radiation syndrome requires the largest
exposure before the associated effects become
apparent?
(A) Hematopoietic
(B) Gastrointestinal
(C) Central nervous system (CNS)
(D) Skeletal - Answer-(C) Central nervous system (CNS)
12. What is the established annual occupational
dose-equivalent limit for the lens of the eye?
(A) 250 mSv
(B) 150 mSv
(C) 50 mSv
(D) 10 mSv - Answer-(B) 150 mSv
13. Occupational radiation monitoring is required
when it is possible that the individual might receive
more than
(A) 5 mrem
(B) 10 mrem
(C) one-tenth the annual dose limit
(D) one- fourth the annual dose limit - Answer-(C) one-tenth the annual dose limit
, 14. Sources of natural background radiation contributing
to whole-body radiation dose include
1. dental x-rays
2. terrestrial radionuclides
3. internal radionuclides
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3 - Answer-(C) 2 and 3 only
15. Irradiation of water molecules within the body and
their resulting breakdown is termed
(A) epilation
(B) radiolysis
(C) proliferation
(D) repopulation - Answer-(B) radiolysis
16. Diagnostic x-radiation may be correctly described as
(A) low energy, low LET
(B) low energy, high LET
(C) high energy, low LET
(D) high energy, high LET - Answer-A) low energy, low LET
17. Which o the Following is (are) used to account For
the differences in tissue characteristics when determining
effective dose to biologic material?
1. tissue weighting actors (Wt)
2. Radiation weighting actors (Wr)
3. Absorbed dose
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3 - Answer-(A) 1 only
18. The x-ray interaction with matter that is responsible
for the majority of scattered radiation reaching
the image receptor (IR) is
(A) the photoelectric effect