Chapter 2 Radiation Physics Answer Key

5. All of the following are examples of electromagnetic radiation except: a) Visible light b) Radio waves c) MR imaging d) Beta particles 6. Which are the primary components of an x-ray machine? a) Cathode & anode b) Tube head & filters c) Control panel & collimator d) X-ray tube & power supply 7. Which is the purpose of the target in an x-ray tube? a) Remove generated heat b) Stop production of electrons c) Convert electrons into x-ray photons d) Aim the electrons toward the area to be imaged 8. All are characteristics of ideal target material except: a) High melting point b) High vapor pressure c) High atomic number d) High thermal conductivity 9. Copper&which part of x-ray machine dissipates heat: a) Insulting oil b) Metal housing c) Glass envelope d) Electronic focusing cup Page2 1. Which electrons have the greatest binding energy? a) N-shell b) M-shell c) L-shell d) K-sell 2. What type of electrical charge does the electron carry? a) Positive b) Negative c) No charge d) Positive or negative 3. Which statement best describes a matter? a) Composed of electrical neutral atoms b) May be subdivided by chemical methods c) Anything has a mass & occupies space d) Contain inner structures that can be divided 4. Amount of energy required to remove an electron from a given orbital: a) Exceeds the electrostatic force of attraction b) Magnitude related to greater distance from nucleus c) Lost energy as electromagnetic radiation d) Lowest principal quantum number, then lowest angular momentum 15. The total filtration for a dental x-ray machine set at 69 kVp should be: a) 1.0 mm b) 1.5 mm c) 2.0 mm d) 2.5 mm 16. Which is the purpose of collimation of x-ray beam? a) Direct photons b) Intensity beam c) Reduce exposure area d) Adjust for source-to-point distance 17. If the source-to-point distance is increased, then which adjustment should be made to ensure consistent image density? a) Increase kVp b) Decrease mA c) Increase exposure time d) Decrease added filtration 18. Photoelectric interaction is most likely to occur when interacting with: a) Bone b) Dentine c) Soft tissue d) Tooth pulp Page3 10. Which x-ray machine control limits the duration of xray production? a) On/off switch b) Exposure time c) mA d) KVp 11. How many impulses of radiations equivalent occur in one-fourth (1/4) second exposure? a) 9 b) 15 c) 20 d) 30 12. Which is the primary form of radiation produced from an intraoral x-ray tube? a) Particulate b) Secondary c) Characteristic d) Bremsstrahlung (Breaking) 13. Doubling the exposure time will result in: a) Doubling the range of photon energies b) Doubling the number of photons generated c) Decreasing by half the x-ray emission spectrum d) Decreasing by half the number of electrons 14. Which is the purpose of dental x-ray machine filtration? a) Decrease beam intensity b) Reduce the size of the beam c) Regulate the shape of the beam d) Eliminate low-energy photons 23. The distance between the crest of the first wave and the second wave is termed as: a) mA b) wavelength c) kVp d) HVL 24. Photons are bundle of energy has no mass or weight travel in straight line in the speed of light 3x10^8. a) True b) False 25. Choose the correct: a) B: proper kVp,mA,ET b) C: low ET, normal kVp,mA c) A: double mA, half ET d) A+B e) All of above 1 d 10 b 2 b 11 b 3 c 12 d 4 a 13 b 5 d 14 d 6 d 15 b 7 c 16 c 8 b 17 a 9 a 18 a 19 20 21 22 23 24 25 e d b a b a d Page4 19. Choose the correct statement: a) Electrostatic force: attraction between electrons & protons b) Centrifugal force: pulling electrons away from nucleus c) The electron has positive charge d) Bothe electrostatic & centrifugal force are equal in magnitude that’s why the electron is kept in their places e) A+B+D only 20. Which is the primary form of radiation produced from intra-oral x-ray tube? a) Particulate b) Secondary c) Characteristic d) Bremsstrahlung 21. During patient exposure, which type of beam occur frequently? a) Coherent scattering b) Compton scattering c) Photoelectric absorption d) Breaking radiation 22. Low frequency electromagnetic radiation means low energy & long wavelength, and vice versa. a) True b) False