ARRT Radiography Practice Test
ARRT Radiation Protection Practice Questions
Radiation Protection makes up 7 of every 50 questions on a Tigertest ARRT practice test. Here are 10 of the 28 questions on it, each with the answer and the reason.
Updated by the Tigertest team. Based on the ARRT Radiography Examination Content Specifications. Original questions; 50 per test, weighted like the real exam. Not affiliated with ARRT.
1. Which three basic methods reduce occupational exposure?
- A.Badges, aprons and gloves
- B.Time, distance and shielding
- C.Collimation, filtration and grids
- D.kVp, mAs and SID
Answer: B. Less time near the source, more distance from it and shielding between you and it are the cardinal principles behind ALARA.
2. Which single change reduces patient dose most when it can be done?
- A.Lowering kVp by 15%
- B.Shortening the SID
- C.Using a higher grid ratio
- D.Tight collimation
Answer: D. Restricting the beam to the anatomy of interest cuts the volume irradiated, lowering patient dose and scatter. Higher grid ratios need more mAs.
3. Adding filtration to the x-ray beam mainly reduces:
- A.Patient skin dose
- B.Scatter at the detector
- C.Beam average energy
- D.Spatial resolution
Answer: A. Filtration removes low-energy photons that would only be absorbed in the skin, so skin dose falls and the beam's average energy rises.
4. What total filtration does federal regulation require for a tube operated above 70 kVp?
- A.1.0 mm lead equivalent
- B.5.0 mm copper equivalent
- C.2.5 mm aluminum equivalent
- D.0.5 mm aluminum equivalent
Answer: C. NCRP and 21 CFR require at least 2.5 mm aluminum equivalent total filtration for general radiographic units operating above 70 kVp.
5. To lower patient dose while keeping receptor exposure the same, the radiographer can:
- A.Use a smaller focal spot
- B.Shorten the exposure only
- C.Raise kVp and lower mAs
- D.Lower kVp and raise mAs
Answer: C. Higher kVp penetrates better, so far fewer mAs are needed for the same exposure, which lowers dose. Using the 15% rule keeps receptor exposure steady.
6. Why should repeat exposures be avoided whenever possible?
- A.Each adds a full second dose
- B.They damage the grid
- C.They reset the exposure index
- D.They lower spatial resolution
Answer: A. Every repeat adds a full extra exposure to the patient. Good communication, positioning and technique selection prevent most repeats.
7. What is the NCRP annual effective dose limit for occupational exposure?
- A.500 mSv
- B.5 mSv
- C.1 mSv
- D.50 mSv
Answer: D. NCRP Report 116 sets an annual occupational effective dose limit of 50 mSv, with cumulative dose kept under 10 mSv times age in years.
8. Under NCRP Report 116, what is the cumulative effective dose limit for a 30-year-old radiographer?
- A.1,500 mSv
- B.300 mSv
- C.30 mSv
- D.150 mSv
Answer: B. The cumulative limit is 10 mSv times age in years: 10 x 30 = 300 mSv. 1,500 mSv would come from wrongly using the 50 mSv annual figure.
9. Once a radiographer declares a pregnancy, what is the monthly equivalent dose limit to the embryo-fetus?
- A.0.05 mSv
- B.0.5 mSv
- C.5 mSv
- D.1 mSv
Answer: B. NCRP sets 0.5 mSv per month to the embryo-fetus once pregnancy is declared. 5 mSv is the older limit for the whole gestation.
10. What is the annual effective dose limit for a radiography student under 18 years old?
- A.50 mSv
- B.0.5 mSv
- C.5 mSv
- D.1 mSv
Answer: D. Students under 18 are held to the public limit of 1 mSv a year for frequent exposure, not the occupational 50 mSv.
Practice all 28 radiation protection questions, and the rest of the 200-question bank, in the free ARRT training sets. Questions you miss come back until you have mastered them.
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