Q1. The SI unit of electric current is:
a) Volt
b) Ohm
c) Ampere
d) Watt
Answer: c) Ampere (Base unit measuring charge flow per second)
Q2. Which lens is used to correct myopia?
a) Convex
b) Concave
c) Bifocal
d) Cylindrical
Answer: b) Concave (Diverges light rays to focus on retina)
Q3. Sound cannot travel through:
a) Solids
b) Liquids
c) Gases
d) Vacuum
Answer: d) Vacuum (Requires medium for propagation)
Q4. The pH of pure water is:
a) 5
b) 7
c) 10
d) 14
Answer: b) 7 (Neutral on pH scale)
Q5. Which gas is filled in electric bulbs?
a) Oxygen
b) Nitrogen
c) Argon
d) Hydrogen
Answer: c) Argon (Prevents filament oxidation)
Q6. Chemical formula of table salt is:
a) NaCl
b) HCl
c) NaOH
d) KCl
Answer: a) NaCl (Sodium chloride, common edible salt)
Q7. Largest gland in the human body is:
a) Pancreas
b) Liver
c) Thyroid
d) Pituitary
Answer: b) Liver (Weighs ~1.5 kg; detoxifies blood)
Q8. Photosynthesis occurs in which cell organelle?
a) Mitochondria
b) Chloroplast
c) Nucleus
d) Ribosome
Answer: b) Chloroplast (Contains chlorophyll pigment)
Q9. Normal human blood pressure is:
a) 120/80 mmHg
b) 140/90 mmHg
c) 100/60 mmHg
d) 160/100 mmHg
Answer: a) 120/80 mmHg (Optimal for adults)
Q10. Ozone layer protects Earth from:
a) UV rays
b) IR rays
c) X-rays
d) Gamma rays
Answer: a) UV rays (Prevents skin cancer and mutations)
Q11. Main component of biogas is:
a) Methane
b) Ethane
c) Propane
d) Butane
Answer: a) Methane (50-75% of biogas composition)
Q12. Which law states "Every action has an equal and opposite reaction"?
a) Newton's 1st Law
b) Newton's 2nd Law
c) Newton's 3rd Law
d) Pascal's Law
Answer: c) Newton's 3rd Law (Fundamental principle of motion)
Q13. Unit of frequency is:
a) Hertz
b) Decibel
c) Ohm
d) Watt
Answer: a) Hertz (Hz) (Measures cycles per second)
Q14. Which mirror is used in vehicle headlights?
a) Plane mirror
b) Concave mirror
c) Convex mirror
d) Spherical mirror
Answer: b) Concave mirror (Focuses light into parallel beams)
Q15. Most abundant gas in Earth's atmosphere is:
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Argon
Answer: c) Nitrogen (78%)
Q16. Vinegar contains which acid?
a) Citric acid
b) Acetic acid
c) Lactic acid
d) Formic acid
Answer: b) Acetic acid (CH₃COOH)
Q17. Chemical symbol for gold is:
a) Ag
b) Au
c) Fe
d) Pb
Answer: b) Au (from Latin 'Aurum')
Q18. The study of insects is called:
a) Ornithology
b) Entomology
c) Ichthyology
d) Herpetology
Answer: b) Entomology
Q19. Which vitamin is produced by human skin in sunlight?
a) Vitamin A
b) Vitamin B12
c) Vitamin C
d) Vitamin D
Answer: d) Vitamin D (Prevents rickets)
Q20. The functional unit of the kidney is:
a) Neuron
b) Nephron
c) Alveoli
d) Hepatocyte
Answer: b) Nephron (Filters blood)
Q21. Chipko Movement was related to:
a) Water conservation
b) Forest conservation
c) Air pollution
d) Wildlife protection
Answer: b) Forest conservation (1970s tree-hugging movement)
Q22. Main greenhouse gas is:
a) Carbon dioxide
b) Methane
c) Water vapor
d) Nitrous oxide
Answer: c) Water vapor (Natural greenhouse effect)
Q23. Which device converts mechanical energy into electrical energy?
a) Motor
b) Generator
c) Transformer
d) Rectifier
Answer: b) Generator (Works on electromagnetic induction principle)
Q24. SI unit of luminous intensity is:
a) Candela
b) Lumen
c) Lux
d) Watt
Answer: a) Candela (One of the seven base SI units)
Q25. Color of light with the shortest wavelength is:
a) Red
b) Green
c) Blue
d) Violet
Answer: d) Violet (Visible light spectrum: 380-450 nm)
Q26. Most electronegative element is:
a) Oxygen
b) Nitrogen
c) Fluorine
d) Chlorine
Answer: c) Fluorine (Pauling scale value: 4.0)
Q27. Common name of sodium bicarbonate is:
a) Washing soda
b) Baking soda
c) Bleaching powder
d) Caustic soda
Answer: b) Baking soda (NaHCO₃, used in cooking)
Q28. Which gas is known as 'laughing gas'?
a) Oxygen
b) Nitrogen dioxide
c) Nitrous oxide
d) Carbon monoxide
Answer: c) Nitrous oxide (N₂O) (Used as anesthetic)
Q29. Largest artery in the human body is:
a) Pulmonary artery
b) Aorta
c) Coronary artery
d) Renal artery
Answer: b) Aorta (Originates from left ventricle)
Q30. Which plant hormone promotes cell division?
a) Auxin
b) Gibberellin
c) Cytokinin
d) Abscisic acid
Answer: c) Cytokinin (Works with auxin in cell differentiation)
Q31. Number of chromosomes in human gametes is:
a) 23
b) 46
c) 22
d) 44
Answer: a) 23 (Haploid number, diploid is 46)
Q32. Which law explains why we feel hot when standing near a fire?
a) Newton's Law of Cooling
b) Stefan-Boltzmann Law
c) Radiation Law
d) Conduction Principle
Answer: c) Radiation Law (Heat transfer through infrared waves)
Q33. The working principle of a washing machine is based on:
a) Centripetal force
b) Centrifugal force
c) Gravitational force
d) Frictional force
Answer: b) Centrifugal force (Spins water outward through holes)
Q34. Acid present in ant stings is:
a) Citric acid
b) Formic acid
c) Lactic acid
d) Acetic acid
Answer: b) Formic acid (Methanoic acid, HCOOH)
Q35. Which gas is used in artificial ripening of fruits?
a) Oxygen
b) Carbon dioxide
c) Ethylene
d) Nitrogen
Answer: c) Ethylene (Natural plant hormone that accelerates ripening)
Q36. Part of the brain responsible for memory is:
a) Cerebrum
b) Cerebellum
c) Medulla
d) Hypothalamus
Answer: a) Cerebrum (Frontal lobe stores long-term memories)
Q37. Which plant shows the fastest movement?
a) Sunflower
b) Mimosa pudica
c) Venus flytrap
d) Banyan tree
Answer: b) Mimosa pudica (Leaves fold within seconds when touched)
Q38. The 'Project Tiger' was launched in which year?
a) 1973
b) 1983
c) 1991
d) 2001
Answer: a) 1973 (To protect Bengal tigers in India)
Q39. The most abundant element in Earth's crust is:
a) Silicon
b) Aluminum
c) Oxygen
d) Iron
Answer: c) Oxygen (46.6% by weight, mainly in silicates)
Q40. A pressure cooker works on the principle of:
a) Lowering boiling point
b) Increasing atmospheric pressure
c) Raising boiling point
d) Decreasing vapor pressure
Answer: c) Raising boiling point (Higher pressure increases boiling temperature)
Q41. The blue color of the sky is due to:
a) Reflection
b) Refraction
c) Scattering
d) Dispersion
Answer: c) Scattering (Rayleigh scattering of shorter blue wavelengths)
Q42. Which device converts AC to DC?
a) Transformer
b) Rectifier
c) Transistor
d) Capacitor
Answer: b) Rectifier (Uses diodes to allow current flow in one direction)
Q43. The SI unit of electric power is:
a) Volt
b) Ampere
c) Watt
d) Ohm
Answer: c) Watt (1 Watt = 1 Joule/second)
Q44. Which phenomenon causes the twinkling of stars?
a) Reflection
b) Refraction
c) Scattering
d) Atmospheric refraction
Answer: d) Atmospheric refraction (Due to changing air density layers)
Q45. Chemical used in photography is:
a) Silver bromide
b) Sodium chloride
c) Calcium carbonate
d) Potassium nitrate
Answer: a) Silver bromide (Light-sensitive compound in photographic films)
Q46. Most abundant metal in Earth's crust is:
a) Iron
b) Aluminum
c) Calcium
d) Sodium
Answer: b) Aluminum (8.1% by weight, found in bauxite ore)
Q47. Which gas is used in fire extinguishers?
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Hydrogen
Answer: b) Carbon dioxide (Smothers fire by displacing oxygen)
Q48. Largest cell in the human body is:
a) Red blood cell
b) White blood cell
c) Nerve cell
d) Ovum
Answer: d) Ovum (About 0.1 mm in diameter, visible to naked eye)
Q49. Which plant hormone induces dormancy in seeds?
a) Auxin
b) Gibberellin
c) Abscisic acid
d) Cytokinin
Answer: c) Abscisic acid (Also known as stress hormone)
Q50. The 'Greenhouse effect' is caused by:
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer: c) Carbon dioxide (Traps infrared radiation from Earth)
Q51. Montreal Protocol addresses:
a) Climate change
b) Ozone depletion
c) Biodiversity loss
d) Water pollution
Answer: b) Ozone depletion (Phases out ozone-depleting substances like CFCs)
Q52. A clinical thermometer measures temperature up to:
a) 42°C
b) 100°C
c) 212°C
d) 50°C
Answer: a) 42°C (Designed for human body temperature range)
Q53. The principle behind a pressure cooker is:
a) Reduced cooking time
b) Increased boiling point
c) Decreased pressure
d) Enhanced flavor
Answer: b) Increased boiling point (Higher pressure raises water's boiling temperature)
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