Radiologic Technologist Exam (ARRT)
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
Question 1
What is the primary purpose of the radiographic exposure factor kVp?
A. Control image density
B. Control beam quality (penetration)
C. Control patient motion
D. Control exposure time
Correct Answer: B. Control beam quality (penetration)
Rationale: kVp determines the energy and penetrating ability of the X-ray beam,
affecting contrast and beam quality.
Question 2
Which unit measures radiation exposure in air?
A. Gray
B. Sievert
C. Roentgen
D. Rad
Correct Answer: C. Roentgen
Rationale: Roentgen measures ionization in air from X-ray or gamma radiation.
,Question 3
Which body tissue is most radiosensitive?
A. Muscle
B. Bone
C. Nerve tissue
D. Lymphatic tissue
Correct Answer: D. Lymphatic tissue
Rationale: Rapidly dividing cells like lymphatic tissue are more sensitive to
radiation.
Question 4
What is the function of the collimator?
A. Increase mA
B. Reduce scatter radiation
C. Increase kVp
D. Measure dose
Correct Answer: B. Reduce scatter radiation
Rationale: Collimation limits beam size, reducing scatter and improving image
quality.
Question 5
Which interaction is most responsible for image contrast in diagnostic
radiography?
A. Pair production
B. Compton scatter
C. Photoelectric effect
D. Bremsstrahlung
Correct Answer: C. Photoelectric effect
,Rationale: The photoelectric effect contributes to differential absorption,
producing contrast.
Question 6
What is the primary function of mA in radiography?
A. Controls beam energy
B. Controls quantity of X-rays produced
C. Controls image sharpness
D. Controls scatter radiation
Correct Answer: B. Controls quantity of X-rays produced
Rationale: mA determines how many electrons are produced, affecting beam
quantity.
Question 7
What is the primary purpose of a grid?
A. Increase image blur
B. Reduce scatter reaching the image receptor
C. Increase exposure time
D. Reduce kVp
Correct Answer: B. Reduce scatter reaching the image receptor
Rationale: Grids absorb scatter radiation before it reaches the detector.
Question 8
Which radiation protection principle involves minimizing exposure time?
A. Shielding
B. Distance
C. Time
D. ALARA
, Correct Answer: C. Time
Rationale: Reducing exposure time decreases total radiation dose.
Question 9
What is ALARA?
A. A radiation detector
B. A type of X-ray tube
C. A radiation safety principle
D. A measurement unit
Correct Answer: C. A radiation safety principle
Rationale: ALARA stands for "As Low As Reasonably Achievable" for radiation
exposure.
Question 10
Which structure produces X-rays in the tube?
A. Anode
B. Cathode
C. Filament only
D. Glass envelope
Correct Answer: A. Anode
Rationale: X-rays are produced when electrons strike the anode target.
Question 11
What is the function of the cathode?
A. Produces electrons
B. Produces X-rays
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
Question 1
What is the primary purpose of the radiographic exposure factor kVp?
A. Control image density
B. Control beam quality (penetration)
C. Control patient motion
D. Control exposure time
Correct Answer: B. Control beam quality (penetration)
Rationale: kVp determines the energy and penetrating ability of the X-ray beam,
affecting contrast and beam quality.
Question 2
Which unit measures radiation exposure in air?
A. Gray
B. Sievert
C. Roentgen
D. Rad
Correct Answer: C. Roentgen
Rationale: Roentgen measures ionization in air from X-ray or gamma radiation.
,Question 3
Which body tissue is most radiosensitive?
A. Muscle
B. Bone
C. Nerve tissue
D. Lymphatic tissue
Correct Answer: D. Lymphatic tissue
Rationale: Rapidly dividing cells like lymphatic tissue are more sensitive to
radiation.
Question 4
What is the function of the collimator?
A. Increase mA
B. Reduce scatter radiation
C. Increase kVp
D. Measure dose
Correct Answer: B. Reduce scatter radiation
Rationale: Collimation limits beam size, reducing scatter and improving image
quality.
Question 5
Which interaction is most responsible for image contrast in diagnostic
radiography?
A. Pair production
B. Compton scatter
C. Photoelectric effect
D. Bremsstrahlung
Correct Answer: C. Photoelectric effect
,Rationale: The photoelectric effect contributes to differential absorption,
producing contrast.
Question 6
What is the primary function of mA in radiography?
A. Controls beam energy
B. Controls quantity of X-rays produced
C. Controls image sharpness
D. Controls scatter radiation
Correct Answer: B. Controls quantity of X-rays produced
Rationale: mA determines how many electrons are produced, affecting beam
quantity.
Question 7
What is the primary purpose of a grid?
A. Increase image blur
B. Reduce scatter reaching the image receptor
C. Increase exposure time
D. Reduce kVp
Correct Answer: B. Reduce scatter reaching the image receptor
Rationale: Grids absorb scatter radiation before it reaches the detector.
Question 8
Which radiation protection principle involves minimizing exposure time?
A. Shielding
B. Distance
C. Time
D. ALARA
, Correct Answer: C. Time
Rationale: Reducing exposure time decreases total radiation dose.
Question 9
What is ALARA?
A. A radiation detector
B. A type of X-ray tube
C. A radiation safety principle
D. A measurement unit
Correct Answer: C. A radiation safety principle
Rationale: ALARA stands for "As Low As Reasonably Achievable" for radiation
exposure.
Question 10
Which structure produces X-rays in the tube?
A. Anode
B. Cathode
C. Filament only
D. Glass envelope
Correct Answer: A. Anode
Rationale: X-rays are produced when electrons strike the anode target.
Question 11
What is the function of the cathode?
A. Produces electrons
B. Produces X-rays
