Questions

  1. Define 1 becquerel (Bq).
  2. Convert 1 gigawatt (GW) to watts.
  3. What is the difference between absorb and transmit in the context of light?
  4. Explain the term accurate in scientific measurements.
  5. Describe the composition of an alpha particle.
  6. How is amplitude measured in a wave?
  7. What is the relationship between the angle of incidence and angle of reflection?
  8. What causes an anomalous result in an experiment?
  9. Define atomic number.
  10. How is background count detected using a Geiger-Müller tube?
  11. What are the sources of background radiation?
  12. Describe a beta particle.
  13. Explain why light cannot escape a black hole.
  14. How does braking distance relate to vehicle safety?
  15. What is the purpose of calibrating a measuring instrument?
  16. Give an example of a categoric variable.
  17. What is the centre of mass of an object?
  18. Define a closed system in physics.
  19. How is a concave lens represented in ray diagrams?
  20. What is a contact force?
  21. Explain the term continuous variable.
  22. Why are control variables important in experiments?
  23. How does a convex lens differ from a concave lens?
  24. What is the function of crumple zones in cars?
  25. Define dependent variable.
  26. How does diffuse reflection differ from specular reflection?
  27. What does directly proportional mean? Give an example.
  28. Define displacement and how it differs from distance.
  29. Explain the term dissipate in energy transfers.
  30. What is elastic deformation?
  31. Define electric current and its unit.
  32. Describe the role of electrons in an atom.
  33. What is an ethical issue in scientific research?
  34. How is extension calculated for a spring?
  35. What is extrapolation in data analysis?
  36. How does a fair test ensure valid results?
  37. Define fluid and give two examples.
  38. What is flux density in magnetism?
  39. Define focal length of a lens.
  40. State Newton’s first law of motion related to inertia.
  41. How is intensity of radiation calculated?
  42. What does inversely proportional mean? Give an example.
  43. Define isotopes and their atomic structure.
  44. What happens beyond the limit of proportionality for a spring?
  45. Compare longitudinal and transverse waves.
  46. What is the main sequence stage of a star?
  47. How is mass number calculated?
  48. Describe a neutron star.
  49. What is a non-contact force? Give an example.
  50. Explain why a non-ohmic resistor’s current is not proportional to voltage.
  51. Name three non-renewable energy resources.
  52. What is the normal line in wave diagrams?
  53. Define nuclear fusion and where it occurs.
  54. How does an ohmic conductor behave under varying voltage?
  55. What is peer review in scientific research?
  56. Define the period of a wave.
  57. How does a permanent magnet differ from an induced magnet?
  58. What is potential difference (p.d.) and its unit?
  59. Explain the difference between precise and accurate measurements.
  60. What is the principal focus of a convex lens?
  61. State the principle of moments.
  62. Describe the structure of a protostar.
  63. What are P-waves and how do they travel?
  64. How do random errors affect experimental data?
  65. Define range in the context of data collection.
  66. What is a real image and how is it formed?
  67. Describe the life cycle of a red giant star.
  68. How does a relay work in electrical circuits?
  69. Name three renewable energy resources.
  70. What is the difference between repeatable and reproducible results?
  71. How does a resistor affect current in a circuit?
  72. Define resolution of a measuring instrument.
  73. What is a resultant force?
  74. Explain the term risk assessment in experiments.
  75. How is a scalar quantity different from a vector?
  76. What is the role of slip-rings in a generator?
  77. Define specular reflection.
  78. How is stopping distance calculated?
  79. What causes a supernova?
  80. Compare S-waves and P-waves.
  81. What is terminal velocity?
  82. Define thinking distance in vehicle safety.
  83. How does a translucent material differ from a transparent one?
  84. What is the equation for work done?
  85. Define zero error in measurements.
  86. Calculate the work done when a force of 12 N12 N moves an object 5 m5 m.
  87. A spring extends by 0.2 m0.2 m under a force of 10 N10 N. Calculate its spring constant.
  88. A radioactive sample has a half-life of 5 years5 years. What mass remains from 80 g80 g after 15 years15 years?
  89. A wave has a frequency of 50 Hz50 Hz and wavelength 0.4 m0.4 m. Calculate its speed.
  90. A car accelerates from 0 m/s0 m/s to 20 m/s20 m/s in 10 s10 s. Calculate its acceleration.
  91. Using F=maF=ma, find the force if m=5 kgm=5 kg and a=3 m/s2a=3 m/s2.
  92. Calculate gravitational potential energy (GPE) for a 2 kg2 kg mass lifted 10 m10 m (g=9.8 m/s2g=9.8 m/s2).
  93. A transformer has 200 primary turns and 50 secondary turns. If the input voltage is 240 V240 V, what is the output voltage?
  94. Calculate the power of a device that transfers 600 J600 J of energy in 5 s5 s.
  95. What is the resistance of a component with 6 V6 V across it and 2 A2 A flowing through it?
  96. A wave has a period of 0.02 s0.02 s. Calculate its frequency.
  97. Determine the momentum of a 0.5 kg0.5 kg ball moving at 4 m/s4 m/s.
  98. Using the equation v=u+atv=u+at, find final velocity if u=3 m/su=3 m/s, a=2 m/s2a=2 m/s2, and t=4 st=4 s.
  99. Calculate the pressure exerted by a force of 150 N150 N over an area of 0.5 m20.5 m2.
  100. A convex lens has a focal length of 0.1 m0.1 m. Calculate its power in dioptres.

Detailed Answers

  1. 1 becquerel (Bq) is a unit of radioactivity defined as one nuclear decay or emission of one particle per second.
  2. 1 GW=109 W1 GW=109 W.
  3. Absorb means a medium blocks light; transmit means light passes through.
  4. A measurement is accurate if it is close to the true value.
  5. An alpha particle consists of 2 protons and 2 neutrons (helium nucleus).
  6. Amplitude is the maximum displacement of a wave from its undisturbed position.
  7. The angle of incidence equals the angle of reflection.
  8. An anomalous result deviates from the expected pattern due to errors or variables.
  9. Atomic number is the number of protons in an atom.
  10. Background count is detected using a Geiger-Müller tube, measuring natural environmental radiation.
  11. Sources include cosmic rays, rocks, medical equipment, and nuclear fallout.
  12. A beta particle is a high-speed electron emitted during radioactive decay.
  13. A black hole’s gravity is so strong that even light cannot escape its event horizon.
  14. Braking distance increases with speed and is affected by road conditions and vehicle mass.
  15. Calibrating ensures a measuring instrument’s readings align with a known standard.
  16. Example: Types of material (e.g., wood, metal, plastic).
  17. The centre of mass is the point where an object’s weight appears to act.
  18. A closed system has no external forces; total energy remains constant.
  19. A concave lens is represented as ◯◯ in ray diagrams.
  20. A contact force acts when objects touch (e.g., friction).
  21. A continuous variable has numerical values (e.g., temperature, time).
  22. Control variables ensure only the independent variable affects the outcome.
  23. A convex lens converges light; a concave lens diverges it.
  24. Crumple zones absorb kinetic energy during collisions to reduce passenger injury.
  25. The dependent variable is measured as the outcome of changing the independent variable.
  26. Diffuse reflection scatters light (rough surfaces); specular reflection is mirror-like (smooth surfaces).
  27. Directly proportional: if xx doubles, yy doubles. Example: Ohm’s law (V∝IV∝I for ohmic conductors).
  28. Displacement is distance with direction; distance is scalar.
  29. Dissipate means energy spreads out, often as waste heat.
  30. Elastic deformation is reversible; the object returns to its original shape.
  31. Electric current is the flow of charge (unit: ampere, A).
  32. Electrons orbit the nucleus and carry negative charge.
  33. Ethical issues involve moral judgments (e.g., animal testing, nuclear energy risks).
  34. Extension = stretched length −− original length.
  35. Extrapolation predicts trends beyond measured data.
  36. A fair test controls variables so only the independent variable affects results.
  37. Fluids flow (liquids/gases), e.g., water, air.
  38. Flux density (B) is magnetic field strength (unit: tesla, T).
  39. Focal length is the distance from the lens to its principal focus.
  40. Newton’s first law: An object remains at rest/uniform motion unless acted on by a resultant force.
  41. Intensity=PowerArea (W/m2)Intensity=AreaPower​ (W/m2).
  42. Inversely proportional: if xx doubles, yy halves. Example: I∝1RI∝R1​ (for constant V).
  43. Isotopes have the same protons but different neutrons (e.g., carbon-12 and carbon-14).
  44. Beyond the limit of proportionality, the spring deforms permanently.
  45. Longitudinal waves vibrate parallel to direction (e.g., sound); transverse waves vibrate perpendicular (e.g., light).
  46. Main sequence stars fuse hydrogen into helium (stable phase).
  47. Mass number = protons + neutrons.
  48. A neutron star is dense, composed mainly of neutrons, formed from supernova remnants.
  49. Non-contact forces act without touch (e.g., gravity, magnetism).
  50. Non-ohmic resistors (e.g., diodes) have resistance changing with voltage.
  51. Coal, oil, natural gas.
  52. The normal is a line perpendicular to a surface at the point of incidence.
  53. Nuclear fusion combines light nuclei (e.g., hydrogen into helium) in stars.
  54. Ohmic conductors (e.g., metals) have constant resistance (V∝IV∝I).
  55. Peer review involves experts evaluating research validity before publication.
  56. Period (T) is the time for one wave cycle (unit: seconds).
  57. Permanent magnets retain magnetism; induced magnets only magnetize in a field.
  58. Potential difference is energy transferred per unit charge (unit: volt, V).
  59. Precise = consistent results; accurate = close to true value.
  60. The principal focus is where parallel rays converge after refraction.
  61. Principle of moments: For equilibrium, ∑clockwise moments=∑anticlockwise moments∑clockwise moments=∑anticlockwise moments.
  62. A protostar is a contracting gas cloud heating up before becoming a star.
  63. P-waves are longitudinal seismic waves that travel through solids and liquids.
  64. Random errors cause scatter in data; reduced by averaging repeated measurements.
  65. Range is the difference between the highest and lowest values in data.
  66. A real image is formed by converging light rays and can be projected (e.g., camera image).
  67. A red giant forms when a star exhausts hydrogen, expands, and fuses helium.
  68. A relay uses a small current to switch a larger current in another circuit.
  69. Solar, wind, hydroelectric.
  70. Repeatable: Same researcher gets similar results; reproducible: Others can replicate results.
  71. A resistor limits current; higher resistance reduces current (R=VIR=IV​).
  72. Resolution is the smallest change an instrument can detect (e.g., mm on a ruler).
  73. Resultant force is the vector sum of all forces acting on an object.
  74. Risk assessment identifies hazards and measures to reduce harm.
  75. Scalars have magnitude only (e.g., speed); vectors have magnitude and direction (e.g., velocity).
  76. Slip-rings maintain electrical contact in rotating coils (used in alternators).
  77. Specular reflection occurs on smooth surfaces, producing a clear image.
  78. Stopping distance=thinking distance+braking distanceStopping distance=thinking distance+braking distance.
  79. A supernova is a massive star’s explosion after fusion ceases.
  80. S-waves are transverse and only travel through solids; P-waves are longitudinal and travel through all states.
  81. Terminal velocity occurs when weight equals air resistance (zero resultant force).
  82. Thinking distance is the distance travelled during driver reaction time.
  83. Translucent materials scatter light (e.g., frosted glass); transparent materials allow clear vision (e.g., window glass).
  84. Work=force×distance (W=Fd)Work=force×distance (W=Fd).
  85. Zero error is an instrument’s offset from zero when measuring nothing.
  86. W=12 N×5 m=60 JW=12 N×5 m=60 J.
  87. k=Fx=100.2=50 N/mk=xF​=0.210​=50 N/m.
  88. After 15 years (3 half-lives): 80 g×(12)3=10 g80 g×(21​)3=10 g.
  89. v=fλ=50×0.4=20 m/sv=fλ=50×0.4=20 m/s.
  90. a=ΔvΔt=20−010=2 m/s2a=ΔtΔv​=1020−0​=2 m/s2.
  91. F=5×3=15 NF=5×3=15 N.
  92. GPE=mgh=2×9.8×10=196 JGPE=mgh=2×9.8×10=196 J.
  93. VpVs=NpNs⇒Vs=50200×240=60 VVs​Vp​​=Ns​Np​​⇒Vs​=20050​×240=60 V.
  94. P=Et=6005=120 WP=tE​=5600​=120 W.
  95. R=VI=62=3 ΩR=IV​=26​=3 Ω.
  96. f=1T=10.02=50 Hzf=T1​=0.021​=50 Hz.
  97. p=mv=0.5×4=2 kg m/sp=mv=0.5×4=2 kg m/s.
  98. v=3+(2×4)=11 m/sv=3+(2×4)=11 m/s.
  99. Pressure=ForceArea=1500.5=300 PaPressure=AreaForce​=0.5150​=300 Pa.
  100. Power=1focal length (m)=10.1=10 DPower=focal length (m)1​=0.11​=10 D.