FRCR FRCR Physics and Radiation Safety 2

Question 1

What is the annual occupational whole-body effective dose limit recommended by the NCRP for radiation workers in the US?

Accepted Answer

50 mSv

Answer

20 mSv

Answer

100 mSv

Answer

5 mSv

Question 2

The photoelectric effect is enhanced by which factor in tissue?

Accepted Answer

Atomic number cubed (Z³)

Answer

Photon energy squared

Answer

Tissue density

Answer

Atomic mass

Question 3

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

Accepted Answer

Remove low-energy photons that add dose without contributing to image

Answer

Increase tube output

Answer

Improve spatial resolution

Answer

Reduce scattered radiation reaching detector

Question 4

Radiographic grids are used primarily to:

Accepted Answer

Reduce scattered radiation reaching the detector

Answer

Increase the primary beam intensity

Answer

Improve contrast by adding filtration

Answer

Collimate the primary beam

Question 5

Which phenomenon describes the increase in patient skin dose when the X-ray tube is operated close to the skin?

Accepted Answer

Inverse square law effect

Answer

Backscatter enhancement

Answer

Penumbra effect

Answer

Beam hardening

Question 6

In fluoroscopy, which mode delivers the highest dose rate to the patient?

Accepted Answer

High-dose-rate (boost/magnification) mode

Answer

Standard fluoroscopy mode

Answer

Pulsed fluoroscopy mode

Answer

Last-image-hold mode