1. The spontaneous emission of radiations from unstable nuclei is called:
A) Radioactivity
B) Reflection
C) Refraction
D) Magnetism
2. Radioactivity was discovered by:
A) Rutherford
B) Henri Becquerel
C) Newton
D) Faraday
3. The nucleus of an atom contains:
A) Electrons only
B) Protons only
C) Protons and neutrons
D) Electrons and neutrons
4. Alpha particles are actually:
A) Electrons
B) Protons
C) Gamma rays
D) Helium nuclei
5. Beta particles are:
A) Fast moving electrons
B) Helium nuclei
C) Neutrons
D) Protons
6. Gamma rays are:
A) Charged particles
B) Electromagnetic waves
C) Sound waves
D) Matter waves
7. The penetrating power is maximum for:
A) Alpha rays
B) Beta rays
C) Gamma rays
D) X-rays only
8. The ionizing power is maximum for:
A) Gamma rays
B) Beta rays
C) X-rays
D) Alpha particles
9. Alpha particles carry:
A) Positive charge
B) Negative charge
C) No charge
D) Double negative charge
10. Beta particles carry:
A) Positive charge
B) Negative charge
C) No charge
D) Double positive charge
11. Gamma rays carry:
A) Positive charge
B) Negative charge
C) No charge
D) Variable charge
12. The SI unit of radioactivity is:
A) Curie
B) Tesla
C) Watt
D) Becquerel
13. One becquerel means:
A) One disintegration per second
B) One charge per second
C) One volt per second
D) One joule per second
14. The time in which half of radioactive material decays is called:
A) Mean life
B) Half-life
C) Time constant
D) Atomic period
15. Radioactive decay is:
A) Controlled artificially
B) Reversible
C) Random process
D) Mechanical process
16. The device used to detect radioactivity is:
A) Ammeter
B) Thermometer
C) Voltmeter
D) Geiger counter
17. The process of splitting a heavy nucleus into smaller nuclei is called:
A) Nuclear fission
B) Nuclear fusion
C) Ionization
D) Modulation
18. The process in which light nuclei combine to form heavy nucleus is called:
A) Nuclear fission
B) Nuclear fusion
C) Ionization
D) Radiation
19. The source of energy in the Sun is:
A) Chemical reaction
B) Nuclear fission
C) Nuclear fusion
D) Combustion
20. Uranium-235 is commonly used in:
A) Nuclear reactors
B) Electric motors
C) Optical fibers
D) Loudspeakers
21. A nuclear reactor is used to produce:
A) Sound energy
B) Light energy only
C) Chemical energy
D) Electrical energy
22. The particles present in nucleus are called:
A) Electrons
B) Nucleons
C) Photons
D) Positrons
23. The number of protons in nucleus is called:
A) Atomic number
B) Mass number
C) Neutron number
D) Half-life
24. The sum of protons and neutrons in nucleus is called:
A) Atomic number
B) Charge number
C) Mass number
D) Nuclear constant
25. Isotopes are atoms having same:
A) Mass number
B) Number of neutrons
C) Atomic mass
D) Atomic number
26. The isotope commonly used in cancer treatment is:
A) Cobalt-60
B) Hydrogen-1
C) Oxygen-16
D) Carbon-12
27. Carbon dating is used to determine:
A) Electric current
B) Age of fossils
C) Density of materials
D) Pressure
28. The radiation with least penetrating power is:
A) Gamma rays
B) X-rays
C) Alpha particles
D) Beta particles
29. The radiation with medium penetrating power is:
A) Gamma rays
B) X-rays
C) Alpha particles
D) Beta particles
30. Gamma rays can be stopped effectively by:
A) Thick lead sheet
B) Paper sheet
C) Aluminum foil
D) Plastic sheet
31. Alpha particles can be stopped by:
A) Thick lead plate
B) Paper sheet
C) Iron rod
D) Concrete wall
32. Beta particles can be stopped by:
A) Paper sheet
B) Thick lead plate
C) Aluminum sheet
D) Glass only
33. Excessive exposure to radiations may cause:
A) Cancer
B) Improved vision
C) Better hearing
D) Increased height
34. Radioactive substances are used in medicine for:
A) Cooling
B) Lighting
C) Sound production
D) Diagnosis and treatment
35. Radioisotopes are isotopes that are:
A) Stable
B) Radioactive
C) Neutral
D) Metallic
36. The SI unit of absorbed radiation dose is:
A) Gray
B) Tesla
C) Henry
D) Joule
37. Nuclear fusion requires:
A) Low temperature
B) Low pressure
C) Very high temperature
D) Vacuum only
38. The energy released in nuclear reactions is due to conversion of:
A) Heat into mass
B) Charge into energy
C) Pressure into energy
D) Mass into energy
39. Einstein’s mass-energy relation is:
40. The nucleus of radioactive atom is generally:
A) Stable
B) Unstable
C) Neutral
D) Massless
41. During alpha decay, atomic number decreases by:
A) 1
B) 4
C) 2
D) 0
42. During beta decay, atomic number changes by:
A) 4
B) 2
C) 0
D) 1
43. Gamma radiation usually accompanies:
A) Alpha and beta decay
B) Refraction only
C) Reflection only
D) Sound waves
44. Nuclear reactors use control rods to:
A) Increase temperature
B) Control chain reaction
C) Produce sound
D) Increase voltage
45. The commonly used material for control rods is:
A) Copper
B) Aluminum
C) Cadmium
D) Iron
46. A nuclear chain reaction occurs in:
A) Nuclear fission
B) Reflection
C) Refraction
D) Sound production
47. The radioactive isotope used in smoke detectors is:
A) Uranium-235
B) Carbon-14
C) Cobalt-60
D) Americium-241
48. Which radiation is deflected least in electric field?
A) Alpha particles
B) Gamma rays
C) Beta particles
D) Electrons
49. Radioactivity is a:
A) Nuclear phenomenon
B) Chemical phenomenon
C) Mechanical phenomenon
D) Optical phenomenon
50. The energy released in nuclear reactions is much greater than in:
A) Electrical reactions
B) Mechanical reactions
C) Chemical reactions
D) Optical reactions
