FRCR FRCR Radiation Physics and Dosimetry

Question 1

Which unit is used to express absorbed radiation dose in the SI system?

Accepted Answer

Gray (Gy)

Answer

Sievert (Sv)

Answer

Roentgen (R)

Answer

Becquerel (Bq)

Question 2

What does the radiation weighting factor (wR) account for when calculating equivalent dose?

Accepted Answer

Biological effectiveness of different radiation types

Answer

Energy of the radiation beam

Answer

Distance from the radiation source

Answer

Density of the irradiated tissue

Question 3

Which of the following best describes the half-value layer (HVL) of an X-ray beam?

Accepted Answer

Thickness of material that reduces beam intensity by 50%

Answer

Depth at which dose is half of the surface dose

Answer

Distance at which the dose rate is halved

Answer

Layer of tissue absorbing half the photon energy

Question 4

In X-ray production, which interaction is primarily responsible for the continuous bremsstrahlung spectrum?

Accepted Answer

Deceleration of electrons in the Coulomb field of nuclei

Answer

Photoelectric absorption by target atoms

Answer

Compton scattering of electrons

Answer

Pair production in the target material

Question 5

What is the primary purpose of added filtration in a diagnostic X-ray tube?

Accepted Answer

Remove low-energy photons to reduce patient skin dose

Answer

Increase the overall intensity of the X-ray beam

Answer

Sharpen image resolution by collimating the beam

Answer

Reduce characteristic radiation from the target

Question 6

Which quantity is used to express the stochastic radiation risk to a whole organism accounting for tissue sensitivity?

Accepted Answer

Effective dose (Sieverts)

Answer

Absorbed dose (Gray)

Answer

Equivalent dose (Sieverts)

Answer

Air kerma (Gray)