Science PSC MCQs – Mix of Physics + Chemistry + Biology

 

Q1. The chemical formula of water is:
A) H₂O ✅ B) CO₂ C) NH₃ D) H₂SO₄

Q2. The unit of electric current is:
A) Volt B) Watt C) Ampere ✅ D) Ohm

Q3. The metal present in thermometers is:
A) Copper B) Mercury ✅ C) Silver D) Sodium

Q4. Photosynthesis occurs in which part of a plant?
A) Root B) Stem C) Leaf ✅ D) Flower

Q5. The gas used by plants during photosynthesis:
A) Oxygen B) Carbon dioxide ✅ C) Nitrogen D) Hydrogen

Q6. The hardest natural substance on Earth:
A) Iron B) Diamond ✅ C) Quartz D) Copper

Q7. The SI unit of force is:
A) Joule B) Newton ✅ C) Pascal D) Watt

Q8. The process of conversion of liquid to gas is called:
A) Condensation B) Evaporation ✅ C) Freezing D) Melting

Q9. The largest gland in the human body is:
A) Pancreas B) Liver ✅ C) Thyroid D) Kidney

Q10. Which vitamin is produced in our skin by sunlight?
A) Vitamin A B) Vitamin B C) Vitamin C D) Vitamin D ✅

Q11. Which gas is known as laughing gas?
A) CO₂ B) N₂O ✅ C) O₂ D) H₂

Q12. The powerhouse of the cell is:
A) Ribosome B) Mitochondria ✅ C) Nucleus D) Chloroplast

Q13. The smallest unit of matter is:
A) Atom ✅ B) Molecule C) Cell D) Electron

Q14. The metal that is liquid at room temperature:
A) Sodium B) Mercury ✅ C) Calcium D) Aluminium

Q15. The instrument used to measure temperature:
A) Barometer B) Hygrometer C) Thermometer ✅ D) Pyrometer

Q16. The gas used for respiration by humans:
A) Nitrogen B) Oxygen ✅ C) Carbon dioxide D) Hydrogen

Q17. The disease caused by deficiency of Vitamin C:
A) Rickets B) Scurvy ✅ C) Night blindness D) Goitre

Q18. The purest form of water is:
A) Rain water ✅ B) River water C) Lake water D) Tap water

Q19. The process of water cycle is called:
A) Photosynthesis B) Hydrological cycle ✅ C) Respiration D) Osmosis

Q20. The planet known as the “Red Planet” is:
A) Earth B) Venus C) Mars ✅ D) Jupiter

Q21. The chemical formula of common salt:
A) CO₂ B) HCl C) NaCl ✅ D) KOH

Q22. Sound cannot travel through:
A) Solids B) Liquids C) Gases D) Vacuum ✅

Q23. The process of conversion of solid to gas directly:
A) Sublimation ✅ B) Condensation C) Fusion D) Evaporation

Q24. The bone that protects the brain:
A) Rib cage B) Skull ✅ C) Spine D) Pelvis

Q25. Which of the following is a non-metal?
A) Iron B) Gold C) Silver D) Sulphur ✅

Q26. The smell of onion is due to the presence of:
A) Sulphur ✅ B) Chlorine C) Phosphorus D) Carbon

Q27. The closest star to Earth (after the Sun) is:
A) Mars B) Proxima Centauri ✅ C) Sirius D) Alpha Centauri

Q28. The instrument used to measure blood pressure:
A) Stethoscope B) Sphygmomanometer ✅ C) Thermometer D) Barometer

Q29. The process of conversion of gas to liquid is:
A) Evaporation B) Condensation ✅ C) Sublimation D) Melting

Q30. The organ that purifies blood in the human body:
A) Pancreas B) Kidney ✅ C) Liver D) Heart

Q31. Earth's atmosphere contains maximum:
A) Oxygen B) Carbon dioxide C) Nitrogen ✅ D) Hydrogen

Q32. The study of plants is called:
A) Zoology B) Botany ✅ C) Geology D) Biology

Q33. The metal used in making filaments of bulbs:
A) Copper B) Silver C) Tungsten ✅ D) Aluminium

Q34. The speed of light is approximately:
A) 3 × 10⁸ m/s ✅ B) 3 × 10⁶ m/s C) 3 × 10⁵ m/s D) 3 × 10⁷ m/s

Q35. Water boils at 100°C at:
A) High pressure B) Low pressure C) Normal atmospheric pressure ✅ D) Vacuum

Q36. The planet that is known as Earth’s twin:
A) Mars B) Venus ✅ C) Jupiter D) Saturn

Q37. Which part of the plant absorbs water?
A) Stem B) Root ✅ C) Leaf D) Flower

Q38. The major gas in LPG is:
A) Methane B) Propane C) Butane ✅ D) Ethane

Q39. The study of earthquakes is called:
A) Seismology ✅ B) Ecology C) Geology D) Oceanography

Q40. Which vitamin is called “Sunshine Vitamin”?
A) Vitamin A B) Vitamin B C) Vitamin C D) Vitamin D ✅

Q41. The colour of chlorophyll is:
A) Yellow B) Red C) Green ✅ D) Blue

Q42. The force that attracts objects towards the Earth:
A) Friction B) Gravity ✅ C) Magnetism D) Pressure

Q43. The chemical symbol of gold is:
A) Au ✅ B) Ag C) Fe D) Pb

Q44. The gas used for filling balloons:
A) Nitrogen B) Hydrogen C) Helium ✅ D) Oxygen

Q45. The major component of bones and teeth is:
A) Calcium ✅ B) Iron C) Potassium D) Sodium

Q46. The blood cells responsible for oxygen transport:
A) WBC B) Platelets C) RBC ✅ D) Plasma

Q47. The SI unit of energy is:
A) Watt B) Joule ✅ C) Newton D) Volt

Q48. Sleeping sickness is caused by:
A) Virus B) Bacteria C) Protozoa ✅ D) Fungi

Q49. The instrument used to see tiny objects:
A) Telescope B) Microscope ✅ C) Periscope D) Endoscope

Q50. The first artificial satellite launched by USSR in 1957:
A) Explorer 1 B) Aryabhata C) Sputnik 1 ✅ D) INSAT-1A

Q51. The study of plants is called:
A) Zoology B) Biology C) Botany ✅ D) Anatomy

Q52. The study of animals is called:
A) Zoology ✅ B) Botany C) Ecology D) Pathology

Q53. The chemical symbol of Iron is:
A) Ir B) Fe ✅ C) I D) In

Q54. The gas used in the manufacture of fertilizers:
A) Oxygen B) Nitrogen ✅ C) Hydrogen D) Carbon dioxide

Q55. The organ that purifies blood in humans:
A) Heart B) Kidney ✅ C) Lungs D) Liver

Q56. The fastest planet to revolve around the sun:
A) Mercury ✅ B) Venus C) Earth D) Mars

Q57. The speed of light is approximately:
A) 3 × 10⁸ m/s ✅ B) 3 × 10⁶ m/s C) 3 × 10⁴ m/s D) 3 × 10¹⁰ m/s

Q58. The element essential for breathing and combustion:
A) Carbon B) Hydrogen C) Oxygen ✅ D) Nitrogen

Q59. The green pigment in plants is called:
A) Carotene B) Chlorophyll ✅ C) Haemoglobin D) Cytoplasm

Q60. The acid present in lemon:
A) Tartaric acid B) Citric acid ✅ C) Acetic acid D) Formic acid

Q61. The outermost layer of the earth is called:
A) Core B) Mantle C) Crust ✅ D) Plate

Q62. Which organ pumps blood in the human body?
A) Brain B) Heart ✅ C) Kidney D) Lungs

Q63. The device used to convert electrical energy into mechanical energy:
A) Generator B) Motor ✅ C) Transformer D) Battery

Q64. The largest planet in the solar system:
A) Earth B) Saturn C) Jupiter ✅ D) Neptune

Q65. The gas responsible for global warming:
A) Oxygen B) Carbon dioxide ✅ C) Nitrogen D) Ozone

Q66. The process of separating cream from milk is:
A) Filtration B) Sedimentation C) Centrifugation ✅ D) Decantation

Q67. The process by which plants lose water through leaves:
A) Transpiration ✅ B) Respiration C) Perspiration D) Absorption

Q68. The blood cells that carry oxygen are:
A) WBC B) RBC ✅ C) Platelets D) Plasma

Q69. The mirror used by dentists is:
A) Convex B) Concave ✅ C) Plane D) Cylindrical

Q70The nearest planet to Earth:
A) Mars B) Venus ✅ C) Mercury D) Jupiter

Q71. The instrument used to measure pressure:
A) Thermometer B) Barometer ✅ C) Ammeter D) Voltmeter

Q72. The process of converting milk into curd:
A) Fermentation ✅ B) Condensation C) Pasteurization D) Evaporation

Q73. The organ that controls all body functions:
A) Brain ✅ B) Heart C) Lungs D) Liver

Q74. The planet known as the “Blue Planet”:
A) Mars B) Earth ✅ C) Venus D) Neptune

Q75. The chemical formula of carbon dioxide:
A) CO B) CO₂ ✅ C) C₂O D) C₂O₂