1. What is the main interaction responsible for image formation in diagnostic X-rays?
(A) Photoelectric effect
(B) Compton scattering
(C) Pair production
(D) Coherent scattering
2. The half-value layer (HVL) of an X-ray beam is a measure of its:
(A) Intensity
(B) Energy
(C) Penetrability
(D) Frequency
3. The SI unit of absorbed dose is:
(A) Gray (Gy)
(B) Becquerel (Bq)
(C) Sievert (Sv)
(D) Rad
4. In MRI, the Larmor frequency is directly proportional to:
(A) Temperature
(B) Magnetic field strength
(C) Relaxation time
(D) Proton density
5. What is the typical energy of diagnostic X-ray photons?
(A) 0.1 – 1 keV
(B) 1 – 10 keV
(C) 30 – 150 keV
(D) 1 – 2 MeV
6. The effective dose takes into account:
(A) Type of radiation only
(B) Absorbed dose only
(C) Sensitivity of the organ and type of radiation
(D) Mass of the organ
7. Which component of the CT scanner rotates around the patient?
(A) X-ray tube only
(B) Detector array only
(C) Gantry
(D) Both X-ray tube and detectors
8. Which radiation interaction dominates in soft tissues at diagnostic energies?
(A) Compton scattering
(B) Photoelectric effect
(C) Pair production
(D) Coherent scattering
9. The most appropriate shielding material for diagnostic X-rays is:
(A) Aluminium
(B) Plastic
(C) Lead
(D) Copper
10. In ultrasound imaging, axial resolution is improved by:
(A) Lower frequency transducer
(B) Increasing wavelength
(C) Higher frequency transducer
(D) Increasing beam width