TEXAS RADIATION SAFETY OFFICER (RSO)
CERTIFICATION EXAM PRACTICE QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. Which of the following types of radiation is classified as
non-ionizing?
A. Alpha particles
B. Beta particles
C. Gamma rays
D. Microwaves
Rationale: Microwaves are non-ionizing radiation because
they do not have enough energy to remove electrons from
atoms or molecules.
2. What is the primary responsibility of a Radiation Safety
Officer?
A. Prescribing radiation therapy
B. Ensuring radiation protection and compliance with
regulations
C. Operating nuclear reactors
D. Performing radiologic imaging
Rationale: The RSO ensures that radiation protection
,measures are in place and that regulatory requirements are
met.
3. What is the SI unit for absorbed dose of radiation?
A. Roentgen (R)
B. Curie (Ci)
C. Gray (Gy)
D. Sievert (Sv)
Rationale: Gray (Gy) is the SI unit representing absorbed dose;
1 Gy = 1 joule/kilogram.
4. Which of the following personal dosimeters is used to
measure cumulative radiation exposure over time?
A. Geiger-Muller counter
B. Thermoluminescent dosimeter (TLD)
C. Scintillation detector
D. Ionization chamber
Rationale: TLDs record cumulative exposure and are
commonly used for monitoring occupational dose.
5. The ALARA principle stands for:
A. As Low As Reasonably Achievable
B. As Long As Radiation Accumulates
C. All Levels Are Radiologically Acceptable
D. As Low And Radiologically Accurate
,Rationale: ALARA is a key radiation safety principle to
minimize exposure.
6. Which type of radiation has the greatest mass?
A. Beta particle
B. Alpha particle
C. Gamma ray
D. X-ray
Rationale: Alpha particles consist of 2 protons and 2 neutrons,
making them more massive than beta particles or photons.
7. The half-life of a radioactive isotope is defined as:
A. The time it takes for all atoms to decay
B. The time it takes for the isotope to lose 75% of its activity
C. The time required for half of the radioactive nuclei to decay
D. The time it takes for radiation to stop being harmful
Rationale: Half-life measures the time for 50% of radioactive
nuclei to decay.
8. What is the most effective shielding for gamma radiation?
A. Plastic
B. Aluminum
C. Lead
D. Wood
Rationale: Dense materials like lead are most effective at
attenuating gamma rays.
, 9. Which of the following is NOT a method to reduce radiation
exposure?
A. Time
B. Distance
C. Shielding
D. Exposure enhancement
Rationale: Reducing exposure uses time, distance, and
shielding, not increasing exposure.
10. What type of radiation exposure is most hazardous
internally?
A. External gamma exposure
B. External beta exposure
C. Ingestion or inhalation of alpha emitters
D. Ultraviolet light
Rationale: Internal alpha emitters can cause significant
damage to tissues due to high ionization density.
11. The annual occupational dose limit for a radiation worker’s
whole body is:
A. 1 mSv
B. 50 mSv
C. 50 mSv (5 rem)
D. 500 mSv
Rationale: Regulatory limits set whole-body occupational dose
at 50 mSv per year.
CERTIFICATION EXAM PRACTICE QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. Which of the following types of radiation is classified as
non-ionizing?
A. Alpha particles
B. Beta particles
C. Gamma rays
D. Microwaves
Rationale: Microwaves are non-ionizing radiation because
they do not have enough energy to remove electrons from
atoms or molecules.
2. What is the primary responsibility of a Radiation Safety
Officer?
A. Prescribing radiation therapy
B. Ensuring radiation protection and compliance with
regulations
C. Operating nuclear reactors
D. Performing radiologic imaging
Rationale: The RSO ensures that radiation protection
,measures are in place and that regulatory requirements are
met.
3. What is the SI unit for absorbed dose of radiation?
A. Roentgen (R)
B. Curie (Ci)
C. Gray (Gy)
D. Sievert (Sv)
Rationale: Gray (Gy) is the SI unit representing absorbed dose;
1 Gy = 1 joule/kilogram.
4. Which of the following personal dosimeters is used to
measure cumulative radiation exposure over time?
A. Geiger-Muller counter
B. Thermoluminescent dosimeter (TLD)
C. Scintillation detector
D. Ionization chamber
Rationale: TLDs record cumulative exposure and are
commonly used for monitoring occupational dose.
5. The ALARA principle stands for:
A. As Low As Reasonably Achievable
B. As Long As Radiation Accumulates
C. All Levels Are Radiologically Acceptable
D. As Low And Radiologically Accurate
,Rationale: ALARA is a key radiation safety principle to
minimize exposure.
6. Which type of radiation has the greatest mass?
A. Beta particle
B. Alpha particle
C. Gamma ray
D. X-ray
Rationale: Alpha particles consist of 2 protons and 2 neutrons,
making them more massive than beta particles or photons.
7. The half-life of a radioactive isotope is defined as:
A. The time it takes for all atoms to decay
B. The time it takes for the isotope to lose 75% of its activity
C. The time required for half of the radioactive nuclei to decay
D. The time it takes for radiation to stop being harmful
Rationale: Half-life measures the time for 50% of radioactive
nuclei to decay.
8. What is the most effective shielding for gamma radiation?
A. Plastic
B. Aluminum
C. Lead
D. Wood
Rationale: Dense materials like lead are most effective at
attenuating gamma rays.
, 9. Which of the following is NOT a method to reduce radiation
exposure?
A. Time
B. Distance
C. Shielding
D. Exposure enhancement
Rationale: Reducing exposure uses time, distance, and
shielding, not increasing exposure.
10. What type of radiation exposure is most hazardous
internally?
A. External gamma exposure
B. External beta exposure
C. Ingestion or inhalation of alpha emitters
D. Ultraviolet light
Rationale: Internal alpha emitters can cause significant
damage to tissues due to high ionization density.
11. The annual occupational dose limit for a radiation worker’s
whole body is:
A. 1 mSv
B. 50 mSv
C. 50 mSv (5 rem)
D. 500 mSv
Rationale: Regulatory limits set whole-body occupational dose
at 50 mSv per year.
