Natural Science MCQs (51–100) | Physics, Chemistry, Biology | Competitive Exams

 

Natural Science MCQs (51–100) – Page 2

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 Mixed Science (Physics, Chemistry, Biology, Environment)

51. Which instrument measures atmospheric pressure?
    a) Thermometer
    b) Barometer
    c) Hygrometer
    d) Altimeter
    Answer: b


52. Unit of frequency:
    a) Hertz
    b) Joule
    c) Watt
    d) Pascal
    Answer: a


53. Which mirror is used in vehicles?
    a) Concave
    b) Convex
    c) Plane
    d) None
    Answer: b


54. Heat transfer through vacuum:
    a) Conduction
    b) Convection
    c) Radiation
    d) Reflection
    Answer: c


55. Speed of light is:
    a) 3×10⁸ m/s
    b) 3×10⁶ m/s
    c) 3×10⁵ m/s
    d) 3×10⁷ m/s
    Answer: a


56. Which element is a noble gas?
    a) Oxygen
    b) Nitrogen
    c) Helium
    d) Hydrogen
    Answer: c


57. Atomic mass is sum of:
    a) Protons + Electrons
    b) Protons + Neutrons
    c) Electrons + Neutrons
    d) All
    Answer: b


58. Which metal is liquid at room temperature?
    a) Iron
    b) Mercury
    c) Gold
    d) Silver
    Answer: b


59. NaCl is:
    a) Acid
    b) Base
    c) Salt
    d) Gas
    Answer: c


60. Rusting requires:
    a) Oxygen only
    b) Water only
    c) Oxygen + Water
    d) Nitrogen
    Answer: c


61. Human respiratory organ:
    a) Heart
    b) Lungs
    c) Liver
    d) Kidney
    Answer: b


62. Which vitamin is produced by sunlight?
    a) Vitamin A
    b) Vitamin B
    c) Vitamin C
    d) Vitamin D
    Answer: d


63. Blood group system:
    a) ABO
    b) ABC
    c) DEF
    d) XYZ
    Answer: a


64. Insulin controls:
    a) Blood pressure
    b) Sugar level
    c) Temperature
    d) Heart rate
    Answer: b


65. Largest cell:
    a) Nerve cell
    b) Egg cell
    c) Muscle cell
    d) Blood cell
    Answer: b


66. Forest helps in:
    a) Pollution increase
    b) Oxygen supply
    c) Soil erosion
    d) None
    Answer: b


67. Acid rain caused by:
    a) CO2
    b) SO2
    c) O2
    d) H2
    Answer: b


68. Biodegradable waste:
    a) Plastic
    b) Glass
    c) Food waste
    d) Metal
    Answer: c


69. Renewable energy source:
    a) Coal
    b) Petrol
    c) Solar
    d) Diesel
    Answer: c


70. Non-renewable energy:
    a) Wind
    b) Solar
    c) Coal
    d) Hydro
    Answer: c


71. Which lens used in spectacles for myopia?
    a) Convex
    b) Concave
    c) Plane
    d) None
    Answer: b


72. Power = ?
    a) Work/Time
    b) Time/Work
    c) Force×Distance
    d) None
    Answer: a


73. Which wave does not need medium?
    a) Sound
    b) Water
    c) Light
    d) Mechanical
    Answer: c


74. Symbol of gold:
    a) Go
    b) Au
    c) Ag
    d) Gd
    Answer: b


75. pH < 7 means:
    a) Base
    b) Neutral
    c) Acid
    d) Salt
    Answer: c


76. Which is base?
    a) HCl
    b) NaOH
    c) CO2
    d) H2SO4
    Answer: b


77. Chlorophyll color:
    a) Red
    b) Blue
    c) Green
    d) Yellow
    Answer: c


78. Human body temperature:
    a) 30°C
    b) 37°C
    c) 40°C
    d) 20°C
    Answer: b


79. Organ for digestion:
    a) Heart
    b) Stomach
    c) Brain
    d) Lung
    Answer: b


80. Which disease caused by bacteria?
    a) Malaria
    b) Tuberculosis
    c) Dengue
    d) Flu
    Answer: b


81. Which disease caused by virus?
    a) TB
    b) Malaria
    c) COVID-19
    d) Cholera
    Answer: c


82. Malaria spreads by:
    a) Housefly
    b) Mosquito
    c) Dog
    d) Air
    Answer: b


83. Earth’s atmosphere layer:
    a) Troposphere
    b) Lithosphere
    c) Hydrosphere
    d) Biosphere
    Answer: a


84. Ozone layer located in:
    a) Troposphere
    b) Stratosphere
    c) Mesosphere
    d) Thermosphere
    Answer: b


85. Global warming increases:
    a) Ice
    b) Temperature
    c) Rain only
    d) Wind only
    Answer: b


86. SI unit of work:
    a) Watt
    b) Joule
    c) Newton
    d) Volt
    Answer: b


87. Which force opposes motion?
    a) Gravity
    b) Friction
    c) Magnetism
    d) Pressure
    Answer: b


88. Water cycle includes:
    a) Evaporation
    b) Condensation
    c) Precipitation
    d) All
    Answer: d


89. Which gas used in fire extinguisher?
    a) O2
    b) CO2
    c) H2
    d) N2
    Answer: b


90. Which organ purifies blood?
    a) Heart
    b) Kidney
    c) Brain
    d) Lung
    Answer: b


91. Largest planet:
    a) Earth
    b) Mars
    c) Jupiter
    d) Venus
    Answer: c


92. Smallest planet:
    a) Mercury
    b) Mars
    c) Venus
    d) Earth
    Answer: a


93. Which is not planet?
    a) Sun
    b) Earth
    c) Mars
    d) Venus
    Answer: a


94. Which gas plants absorb?
    a) Oxygen
    b) CO2
    c) Nitrogen
    d) Hydrogen
    Answer: b


95. Which energy from Sun?
    a) Chemical
    b) Solar
    c) Nuclear
    d) Wind
    Answer: b


96. Wind energy depends on:
    a) Speed of wind
    b) Temperature
    c) Pressure only
    d) None
    Answer: a


97. Which metal used in wires?
    a) Iron
    b) Copper
    c) Zinc
    d) Lead
    Answer: b


98. Which is conductor?
    a) Plastic
    b) Wood
    c) Copper
    d) Rubber
    Answer: c


99. Which is insulator?
    a) Iron
    b) Copper
    c) Plastic
    d) Silver
    Answer: c


100. Electric bulb converts:
     a) Electrical → Light
     b) Light → Heat
     c) Heat → Sound
     d) None
     Answer: a

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