Properties of α, β, γ radiations MCQs With Answer

Properties of α, β, γ radiations MCQs With Answer are essential for B. Pharm students studying radiation physics, radiopharmacy, and radiation safety. This concise guide covers alpha, beta and gamma radiation properties—penetration power, ionization ability, range, energy, decay modes, shielding materials, detection methods, biological effects and dosimetry—tailored for pharmacy curricula. Learning these radiation characteristics helps in safe handling of radionuclides, sterilization techniques, diagnostic tracers and therapeutic applications. Keywords covered include alpha beta gamma radiation properties, radiation safety, ionization, penetration, half-life, decay, shielding and dosimetry. The questions emphasize conceptual understanding and clinical relevance for B. Pharm practice. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which radiation has the highest ionizing power but the lowest penetration?

• Gamma rays
• Beta particles
• Alpha particles
• Neutrons

Correct Answer: Alpha particles

Q2. Which radiation is most effectively stopped by a few millimeters of aluminum?

• Gamma rays
• Beta particles
• Alpha particles
• X-rays

Correct Answer: Beta particles

Q3. Which radiation requires dense shielding like lead for effective attenuation?

• Alpha particles
• Beta particles
• Gamma rays
• Ultraviolet radiation

Correct Answer: Gamma rays

Q4. Which unit measures activity of a radioactive source in SI units?

• Gray (Gy)
• Sievert (Sv)
• Becquerel (Bq)
• Roentgen (R)

Correct Answer: Becquerel (Bq)

Q5. Which quantity describes the absorbed energy per unit mass by tissue?

• Activity
• Gray (Gy)
• Becquerel (Bq)
• Curie (Ci)

Correct Answer: Gray (Gy)

Q6. Beta-plus decay produces which of the following particles?

• Electron
• Positron
• Alpha particle
• Neutrino only

Correct Answer: Positron

Q7. What happens when a positron meets an electron?

• They form a neutron
• They annihilate producing gamma photons
• They emit beta particles
• They become stable atoms

Correct Answer: They annihilate producing gamma photons

Q8. Which radiation has the longest range in air?

• Alpha particles
• Beta particles
• Gamma rays
• Protons

Correct Answer: Gamma rays

Q9. Linear energy transfer (LET) is highest for which radiation?

• Gamma rays
• Beta particles
• Alpha particles
• X-rays

Correct Answer: Alpha particles

Q10. Relative biological effectiveness (RBE) tends to be higher for radiation with:

• Low LET
• High LET
• High penetration only
• Low energy only

Correct Answer: High LET

Q11. Which detector is commonly used to detect beta and gamma radiation in labs?

• Thermoluminescent dosimeter
• Geiger-Mueller counter
• Photographic film only
• Calorimeter

Correct Answer: Geiger-Mueller counter

Q12. Which process produces Bremsstrahlung radiation when beta particles are decelerated?

• Pair production
• Photoelectric effect
• Bremsstrahlung emission
• Compton scattering

Correct Answer: Bremsstrahlung emission

Q13. Pair production requires photon energy greater than approximately:

• 0.511 keV
• 1.022 MeV
• 10 keV
• 100 MeV

Correct Answer: 1.022 MeV

Q14. Which interaction dominates for gamma photons around intermediate energies in tissue?

• Photoelectric effect
• Compton scattering
• Pair production
• Alpha absorption

Correct Answer: Compton scattering

Q15. Which shielding material is preferred to stop alpha particles in the lab?

• Paper or skin
• Lead sheet
• Thick concrete
• Water only

Correct Answer: Paper or skin

Q16. The half-life of a radionuclide defines:

• The time for activity to double
• The time for activity to reduce by half
• Time for full decay to zero
• Biological clearance time

Correct Answer: The time for activity to reduce by half

Q17. Which radiation is most likely to cause direct ionization of DNA via high LET?

• Gamma rays
• Beta particles
• Alpha particles
• Microwaves

Correct Answer: Alpha particles

Q18. In radiopharmacy, 99mTc is commonly used because it emits:

• Alpha particles
• Beta-minus particles
• Gamma photons
• Neutrons

Correct Answer: Gamma photons

Q19. Which detector provides energy information useful for gamma spectroscopy?

• Geiger-Mueller counter
• Scintillation detector (NaI or Ge)
• Film badge only
• Thermometer

Correct Answer: Scintillation detector (NaI or Ge)

Q20. During beta decay, which particle is also emitted alongside the beta particle?

• Alpha particle
• Neutrino or antineutrino
• Photon only
• Positron always

Correct Answer: Neutrino or antineutrino

Q21. Which effect increases when gamma photons interact with high-Z materials?

• Beta emission
• Photoelectric absorption
• Alpha production
• Electron capture only

Correct Answer: Photoelectric absorption

Q22. What is the main biological concern when handling unshielded beta emitters?

• Whole-body external exposure only
• Skin burns and localized doses due to shallow penetration
• Deep organ irradiation only
• No hazard at all

Correct Answer: Skin burns and localized doses due to shallow penetration

Q23. Which practice follows the ALARA principle?

• Maximizing exposure time
• Minimizing time, maximizing distance, using shielding
• Removing shielding to improve access
• Ignoring dosimeter readings

Correct Answer: Minimizing time, maximizing distance, using shielding

Q24. In alpha decay, the daughter nucleus has:

• Higher atomic number by 2
• Lower atomic number by 2
• Same atomic number
• Higher mass number by 4 only

Correct Answer: Lower atomic number by 2

Q25. Which measurement accounts for biological effect differences between radiation types?

• Gray (Gy)
• Activity (Bq)
• Sievert (Sv)
• Counts per minute (CPM)

Correct Answer: Sievert (Sv)

Q26. Which phenomenon reduces beta particle range in tissue?

• High LET
• Bremsstrahlung and multiple scattering
• Pair production
• Neutron capture

Correct Answer: Bremsstrahlung and multiple scattering

Q27. Which interaction dominates low-energy photon absorption in high atomic number materials?

• Compton scattering
• Photoelectric effect
• Pair production
• Alpha absorption

Correct Answer: Photoelectric effect

Q28. A sealed alpha source is relatively safe externally because:

• Alpha particles are highly penetrating
• Alpha particles cannot penetrate the sealed container or skin
• Alpha sources emit strong gamma radiation
• They produce neutrons

Correct Answer: Alpha particles cannot penetrate the sealed container or skin

Q29. Which radioactive decay involves electron capture?

• Alpha decay
• Beta-minus decay
• Capture of inner-shell electron converting proton to neutron
• Spontaneous fission only

Correct Answer: Capture of inner-shell electron converting proton to neutron

Q30. For gamma shielding, which material is often used for structural protection in facilities?

• Wood
• Concrete
• Paper
• Plastic wrap

Correct Answer: Concrete

Q31. Which quantity describes dose rate absorbed by personnel over time?

• Activity (Bq)
• Absorbed dose rate (Gy/h)
• Mass number
• Half-life

Correct Answer: Absorbed dose rate (Gy/h)

Q32. Which radiation interaction can eject tightly bound inner-shell electrons producing characteristic X-rays?

• Alpha decay only
• Photoelectric effect
• Compton scattering only
• Beta annihilation

Correct Answer: Photoelectric effect

Q33. Which radionuclide decay produces a cascade of gamma photons useful in imaging?

• 99mTc
• Alpha particles only
• Stable iodine
• None produce gamma photons

Correct Answer: 99mTc

Q34. In radiation dosimetry, what is a TLD used to measure?

• Activity concentration
• Absorbed dose via thermoluminescence
• Half-life directly
• Number of alpha particles only

Correct Answer: Absorbed dose via thermoluminescence

Q35. Which statement about gamma rays is correct?

• They are charged particles
• They are high-energy photons with no mass or charge
• They are identical to alpha particles
• They have the highest LET

Correct Answer: They are high-energy photons with no mass or charge

Q36. Contamination control in radiopharmacy is most concerned with which types of emitters?

• Only gamma emitters
• Beta and alpha emitters that can contaminate surfaces and be ingested
• Only neutron emitters
• Ultraviolet emitters

Correct Answer: Beta and alpha emitters that can contaminate surfaces and be ingested

Q37. Which instrument measures ionizing radiation by producing an electrical pulse when radiation ionizes gas?

• Geiger-Mueller counter
• Thermocycler
• pH meter
• Optical microscope

Correct Answer: Geiger-Mueller counter

Q38. Which property differentiates beta-minus from beta-plus decay?

• Beta-minus emits positrons
• Beta-plus emits electrons
• Beta-minus converts neutron to proton and emits electron
• Both are identical processes

Correct Answer: Beta-minus converts neutron to proton and emits electron

Q39. What is the main risk of working with high-energy beta emitters near high-Z shielding?

• Production of alpha radiation
• Enhanced Bremsstrahlung X-ray production
• Loss of activity
• Instant decay to stable isotopes

Correct Answer: Enhanced Bremsstrahlung X-ray production

Q40. Which factor increases the probability of photoelectric absorption?

• Lower Z of absorber
• Higher photon energy always
• Higher atomic number (Z) of absorber and lower photon energy
• Only thickness matters

Correct Answer: Higher atomic number (Z) of absorber and lower photon energy

Q41. Which biological effect is commonly associated with acute high-dose radiation?

• Chronic cough only
• Acute radiation syndrome (ARS)
• Immediate cancer cure
• No effects at all

Correct Answer: Acute radiation syndrome (ARS)

Q42. What is the role of chelating agents in radiopharmacy for certain radionuclides?

• They increase gamma energy
• They bind radionuclides to biomolecules for targeted delivery
• They neutralize radioactivity completely
• They produce alpha particles

Correct Answer: They bind radionuclides to biomolecules for targeted delivery

Q43. Which radiation interaction is most likely when gamma photon energy is much greater than 1.022 MeV?

• Photoelectric effect
• Compton scattering
• Pair production
• Alpha decay

Correct Answer: Pair production

Q44. Contamination monitoring commonly uses which measurement unit for surface activity?

• Sievert (Sv)
• Counts per minute (CPM) or disintegrations per minute (DPM)
• Gray (Gy) only
• Volts

Correct Answer: Counts per minute (CPM) or disintegrations per minute (DPM)

Q45. Which radiation is emitted during nuclear transmutation when a nucleus emits two protons and two neutrons?

• Beta particle
• Alpha particle
• Gamma photon only
• Neutrino

Correct Answer: Alpha particle

Q46. In PET imaging, which process is fundamental to image formation?

• Alpha decay
• Positron emission and annihilation producing two 511 keV photons
• Beta-minus decay only
• Neutron activation

Correct Answer: Positron emission and annihilation producing two 511 keV photons

Q47. Which is a major reason to prefer plastic vials over glass for some beta emitters?

• Plastic increases Bremsstrahlung
• Plastic reduces Bremsstrahlung compared to high-Z glass
• Glass prevents all radiation escape
• Plastic makes decay faster

Correct Answer: Plastic reduces Bremsstrahlung compared to high-Z glass

Q48. What is the main advantage of using low-energy gamma emitters in diagnostic imaging?

• Higher patient dose always
• Better tissue penetration without excessive dose if energy optimized
• They produce alpha particles
• No need for shielding

Correct Answer: Better tissue penetration without excessive dose if energy optimized

Q49. Which statement about decay chains is true?

• All radionuclides decay directly to stable isotopes in one step
• Some parent radionuclides decay into radioactive daughters forming a decay series
• Decay chains only occur for artificially produced isotopes
• Daughters are always inert gases

Correct Answer: Some parent radionuclides decay into radioactive daughters forming a decay series

Q50. Which administrative control reduces occupational radiation exposure in a pharmacy setting?

• No training required
• Time scheduling, authorized access, and monitoring with dosimeters
• Leaving sources unmonitored
• Increasing source strength unnecessarily

Correct Answer: Time scheduling, authorized access, and monitoring with dosimeters