STS Test Preparation MCQs

Prepare for STS, IBA, and JST exams 2025 with latest MCQs for Grades 5 to 15 Jobs. Get topic-wise practice questions in Maths, Science, English, Current Affairs, and General Knowledge. Boost your preparation with daily quiz updates.

  1. The most abundant element in the universe is ____?
    a) Helium
    b) Hydrogen
    c) Oxygen
    d) Nitrogen
    Answer: b) Hydrogen
  2. The most abundant element in the Earth’s crust is ____?
    a) Silicon
    b) Aluminum
    c) Oxygen
    d) Iron
    Answer: c) Oxygen
  3. Each day, the human body breathes in ____ liters of air.
    a) 5,000 – 10,000
    b) 15,000 – 20,000
    c) 25,000 – 30,000
    d) 10,000 – 15,000
    Answer: b) 15,000 – 20,000
  4. Deficiency of Vitamin-D results in ____?
    a) Scurvy
    b) Rickets
    c) Beriberi
    d) Night blindness
    Answer: b) Rickets
  5. The SI unit of “pressure” is ____?
    a) Newton
    b) Pascal
    c) Joule
    d) Watt
    Answer: b) Pascal
  6. The most densest substance on the Earth is ____?
    a) Gold
    b) Osmium
    c) Platinum
    d) Lead
    Answer: b) Osmium
  7. For a fixed mass of gas at constant temperature, if we decrease volume, the pressure will ____?
    a) Decrease
    b) Increase
    c) Remain the same
    d) Fluctuate
    Answer: b) Increase
  8. The lifespan of Red Blood Cells is ____ days?
    a) 90
    b) 120
    c) 150
    d) 180
    Answer: b) 120
  9. The density of water is ____?
    a) 0.5 g/cm³
    b) 1 g/cm³
    c) 1.5 g/cm³
    d) 2 g/cm³
    Answer: b) 1 g/cm³
  10. Radioactivity was discovered by ____?
    a) Rutherford
    b) Becquerel
    c) Curie
    d) Einstein
    Answer: b) Becquerel
  11. A device which converts chemical energy into electrical energy is called ____?
    a) Motor
    b) Generator
    c) Battery
    d) Transformer
    Answer: b) Generator
  12. The Sun is a ____?
    a) Planet
    b) Star
    c) Moon
    d) Asteroid
    Answer: b) Star
  13. The gas used in a refrigerator to cool water is ____?
    a) Oxygen
    b) Carbon dioxide
    c) Nitrogen
    d) Freon
    Answer: b) Carbon dioxide
  14. Sound waves are ____ waves.
    a) Transverse
    b) Longitudinal
    c) Electromagnetic
    d) Surface
    Answer: b) Longitudinal
  15. The lifespan of White Blood Cells is ____ day(s)?
    a) 1 – 3
    b) 4 – 21
    c) 30 – 40
    d) 60 – 80
    Answer: b) 4 – 21
  16. The fluid part of blood is known as ____?
    a) Serum
    b) Plasma
    c) Lymph
    d) Hemoglobin
    Answer: b) Plasma
  17. During winter in cold countries, the ____ is mixed to melt the ice on the icy roads.
    a) Sugar
    b) Salt
    c) Sand
    d) Water
    Answer: b) Salt
  18. In a very low temperature, which from the following will freeze at last?
    a) Fresh water
    b) Sea water
    c) River water
    d) Lake water
    Answer: b) Sea water
  19. The nearest planet to the Earth is ____?
    a) Mars
    b) Venus
    c) Mercury
    d) Jupiter
    Answer: b) Venus
  20. GPS is an abbreviation for?
    a) Global Power System
    b) Global Positioning System
    c) General Protection System
    d) Geographic Projection System
    Answer: b) Global Positioning System
  21. A camera uses a ____ to form an image.
    a) Concave lens
    b) Convex lens
    c) Plane mirror
    d) Prism
    Answer: b) Convex lens
  22. Which from the following is NOT a conductor?
    a) Copper
    b) Silver
    c) Glass
    d) Aluminum
    Answer: c) Glass (Note: Corrected assumption based on typical options)
  23. CNG stands for?
    a) Compressed Natural Gas
    b) Carbon Nitrogen Gas
    c) Controlled Natural Gas
    d) Combined Natural Gas
    Answer: a) Compressed Natural Gas
  24. Which from the following is true for “Sound”?
    a) Sound can travel through a vacuum
    b) Sound cannot travel through a vacuum
    c) Sound travels fastest in water
    d) Sound has no frequency
    Answer: b) Sound cannot travel through a vacuum
  25. When white light is passed through a prism, it splits into ____ colours.
    a) 5
    b) 6
    c) 7
    d) 8
    Answer: c) 7
  26. 1 nanometer = ?
    a) 10⁻⁶ meter
    b) 10⁻⁹ meter
    c) 10⁻³ meter
    d) 10⁻¹² meter
    Answer: b) 10⁻⁹ meter
  27. Instrument used for measuring very high temperature is ____?
    a) Thermometer
    b) Barometer
    c) Pyrometer
    d) Hygrometer
    Answer: c) Pyrometer
  28. Oxidation is a chemical reaction involving the ____?
    a) Gain of Electrons
    b) Loss of Electrons
    c) Gain of Protons
    d) Loss of Protons
    Answer: b) Loss of Electrons
  29. At night, Plants intake ____ and release ____?
    a) Oxygen – Carbon dioxide
    b) Carbon dioxide – Oxygen
    c) Nitrogen – Oxygen
    d) Oxygen – Nitrogen
    Answer: b) Carbon dioxide – Oxygen
  30. Urine is produced in ____?
    a) Liver
    b) Kidneys
    c) Lungs
    d) Heart
    Answer: b) Kidneys
  31. Blood is cleaned by ____?
    a) Liver
    b) Kidneys
    c) Spleen
    d) Pancreas
    Answer: b) Kidneys
  32. The salinity of sea water is determined by the amount of common salt (Sodium Chloride) in ____ of sea water.
    a) 100 g
    b) 500 g
    c) 1 kg
    d) 10 kg
    Answer: c) 1 kg
  33. The planet which is easily visible from the Earth is?
    a) Mars
    b) Venus
    c) Jupiter
    d) Saturn
    Answer: b) Venus
  34. The Great Spot is on the planet ____?
    a) Saturn
    b) Jupiter
    c) Uranus
    d) Neptune
    Answer: b) Jupiter
  35. Which is the outermost planet in the solar system?
    a) Uranus
    b) Neptune
    c) Pluto
    d) Saturn
    Answer: b) Neptune
  36. Severe deficiency of Vitamin D results in ____.
    a) Scurvy
    b) Rickets
    c) Anemia
    d) Osteoporosis
    Answer: b) Rickets
  37. Milk contains water ____.
    a) 70%
    b) 80%
    c) 90%
    d) 60%
    Answer: b) 80%
  38. The SI unit of charge is ____?
    a) Volt
    b) Coulomb
    c) Ohm
    d) Ampere
    Answer: b) Coulomb
  39. Very High Frequency (VHF) have ____ wavelengths?
    a) Longer
    b) Shorter
    c) Medium
    d) Variable
    Answer: b) Shorter
  40. Long-sight defect could be corrected by using ____ lens?
    a) Concave
    b) Convex
    c) Cylindrical
    d) Bifocal
    Answer: b) Convex
  41. Short-sight defect could be corrected by a ____ lens?
    a) Convex
    b) Concave
    c) Plane
    d) Bifocal
    Answer: b) Concave
  42. Deficiency of Vitamin-A results in ____?
    a) Rickets
    b) Night blindness
    c) Scurvy
    d) Beriberi
    Answer: b) Night blindness
  43. A camera uses a ____ to form an image.
    a) Concave lens
    b) Convex lens
    c) Plane mirror
    c) Prism
    Answer: b) Convex lens
  44. 1 light year = ?
    a) 9.5×10¹⁰ km
    b) 9.5×10¹¹ km
    c) 9.5×10¹² km
    d) 9.5×10¹³ km
    Answer: c) 9.5×10¹² km
  45. The bodyguard of the Earth is ____ that save the Earth from many Comets and Asteroids.
    a) Mars
    b) Jupiter
    c) Saturn
    d) Uranus
    Answer: b) Jupiter
  46. The planets visible to us without using a telescope are ____?
    a) 2
    b) 3
    c) 4
    d) 5
    Answer: b) 3
  47. According to Big Bang Theory, the Universe began about ____ billion years ago.
    a) 10 – 20
    b) 20 – 30
    c) 30 – 40
    d) 40 – 50
    Answer: c) 30 – 40
  48. Biosensor is used to measure?
    a) Blood pressure
    b) Blood glucose level
    c) Heart rate
    d) Temperature
    Answer: b) Blood glucose level
  49. Einstein’s famous equation which states that mass and energy are interchangeable is?
    a) E = mc
    b) E = mc²
    c) E = m²c
    d) E = mc³
    Answer: b) E = mc²
  50. The SI unit of electric current is?
    a) Volt
    b) Ampere
    c) Ohm
    d) Watt
    Answer: b) Ampere
  51. The principal constituent of the atmosphere of the Earth is?
    a) Oxygen
    b) Nitrogen
    c) Carbon dioxide
    d) Argon
    Answer: b) Nitrogen
  52. What is Dry Ice?
    a) Solid Nitrogen
    b) Solid Carbon Dioxide
    c) Solid Oxygen
    d) Solid Hydrogen
    Answer: b) Solid Carbon Dioxide
  53. Digestion of food is completed in the ____?
    a) Stomach
    b) Small intestine
    c) Large intestine
    d) Esophagus
    Answer: b) Small intestine
  54. Carrot is a good source of Vitamin ____?
    a) Vitamin B
    b) Vitamin A
    c) Vitamin C
    d) Vitamin D
    Answer: b) Vitamin A
  55. For proper formation of teeth, ____ is essential?
    a) Calcium
    b) Fluorine
    c) Iron
    d) Phosphorus
    Answer: b) Fluorine
  56. Deficiency of ____ causes loss of appetite and poor growth?
    a) Iron
    b) Zinc
    c) Magnesium
    d) Potassium
    Answer: b) Zinc
  57. Meteorology is the study of?
    a) Rocks
    b) Winds and clouds
    c) Oceans
    d) Plants
    Answer: b) Winds and clouds
  58. The Carbon Dioxide in the atmosphere, by volume, is ____?
    a) 0.039%
    b) 0.5%
    c) 1%
    d) 5%
    Answer: a) 0.039%
  59. Diamond is an allotropic form of ____?
    a) Silicon
    b) Carbon
    c) Oxygen
    d) Nitrogen
    Answer: b) Carbon
  60. The SI unit of Heat is ____?
    a) Calorie
    b) Joule
    c) Watt
    d) Kelvin
    Answer: b) Joule
  61. The good sources of Vitamin-A are?
    a) Dairy products
    b) Green leafy vegetables
    c) Meat
    d) Grains
    Answer: b) Green leafy vegetables
  62. The good sources of Vitamin-B Complex are?
    a) Fresh vegetables and fruits
    b) Meat and fish
    c) Dairy products
    d) Grains
    Answer: a) Fresh vegetables and fruits
  63. The good sources of Vitamin-C are ____?
    a) Citrus fruits
    b) Fresh vegetables and fruits
    c) Meat
    d) Eggs
    Answer: b) Fresh vegetables and fruits
  64. The good sources of iodine are ____?
    a) Dairy products
    b) Sea foods
    c) Grains
    d) Nuts
    Answer: b) Sea foods
  65. The gas, commonly known as “laughing gas”, is?
    a) Oxygen
    b) Nitrous Oxide
    c) Carbon dioxide
    d) Helium
    Answer: b) Nitrous Oxide
  66. The source of oxygen in photosynthesis is?
    a) Carbon dioxide
    b) Water
    c) Glucose
    d) Nitrogen
    Answer: b) Water
  67. The instrument used to measure wind speed is?
    a) Barometer
    b) Anemometer
    c) Thermometer
    d) Hygrometer
    Answer: b) Anemometer
  68. The natural fats and oils are composed of ____?
    a) Carbon, Hydrogen, and Oxygen
    b) Carbon and Nitrogen
    c) Hydrogen and Oxygen
    d) Carbon and Sulfur
    Answer: a) Carbon, Hydrogen, and Oxygen
  69. The energy value of food is measured in ____?
    a) Calorie
    b) Joule
    c) Watt
    d) Volt
    Answer: b) Joule
  70. Wind energy is the ____ energy.
    a) Potential
    b) Kinetic
    c) Thermal
    d) Chemical
    Answer: b) Kinetic
  71. Who is considered the founder of meteorology?
    a) Galileo
    b) Aristotle
    c) Newton
    d) Copernicus
    Answer: b) Aristotle
  72. Water covers ____ of the Earth’s surface?
    a) 61%
    b) 71%
    c) 81%
    d) 91%
    Answer: b) 71%
  73. In general, wind speed of 10 – 13 kph caused ____?
    a) Severe damage
    b) Moderate damage
    c) Minor or no damage
    d) Major destruction
    Answer: c) Minor or no damage
  74. Acid rain is mainly caused by emissions of ____ in the atmosphere?
    a) Carbon dioxide
    b) Sulfur Dioxide and Nitrogen Oxide
    c) Methane
    d) Oxygen
    Answer: b) Sulfur Dioxide and Nitrogen Oxide
  75. About 50% of the Earth’s crust, including the waters on the Earth and atmosphere, is?
    a) Silicon
    b) Oxygen
    c) Aluminum
    d) Iron
    Answer: b) Oxygen
  76. The fourth state of matter is?
    a) Liquid
    b) Plasma
    c) Gas
    d) Solid
    Answer: b) Plasma
  77. The device used to convert Alternate Current into Direct Current is called?
    a) Transformer
    b) Rectifier
    c) Generator
    d) Inverter
    Answer: b) Rectifier
  78. In night, when photosynthesis is stopped, plants ____?
    a) Release Oxygen
    b) Take in Carbon Dioxide
    c) Release Carbon dioxide
    d) Stop all activity
    Answer: b) Take in Carbon Dioxide
  79. ____ are called the powerhouses of the cell?
    a) Nucleus
    b) Mitochondria
    c) Ribosomes
    d) Endoplasmic reticulum
    Answer: b) Mitochondria
  80. One of the countries through which equator passes is ____?
    a) Brazil
    b) Kenya
    c) India
    d) Russia
    Answer: b) Kenya
  81. Copper can be converted into gold by?
    a) Heating
    b) Artificial radioactivity
    c) Chemical reaction
    d) Electrolysis
    Answer: b) Artificial radioactivity
  82. The three elements needed for healthy growth of plants are ____?
    a) N, P, K
    b) C, H, O
    c) Fe, Mg, Ca
    d) Na, K, Cl
    Answer: a) N, P, K
  83. Clocks, which move with velocities comparable with the velocity of light, run?
    a) Fast
    b) Slow
    c) Normal
    d) Stop
    Answer: b) Slow
  84. Max Planck received the Nobel Prize in Physics in 1918 for his discovery of?
    a) Relativity
    b) Energy quanta
    c) Quantum theory
    d) Photoelectric effect
    Answer: b) Energy quanta
  85. Bronze medal is made up of metals?
    a) Copper, zinc
    b) Copper, tin
    c) Copper, nickel
    d) Copper, silver
    Answer: b) Copper, tin
  86. Addison’s disease is caused by the deficiency of ____?
    a) Insulin
    b) Adrenocorticotrophic Hormone
    c) Thyroxine
    d) Cortisol
    Answer: b) Adrenocorticotrophic Hormone
  87. Humming bird belongs to a category called?
    a) Ectotherm
    b) Endotherm
    c) Poikilotherm
    d) Homeotherm
    Answer: b) Endotherm
  88. Radioactive isotope of Uranium used in Nuclear Bomb is?
    a) U-238
    b) U-235
    c) U-234
    d) U-239
    Answer: b) U-235
  89. Human population growth is greatest in developing countries because?
    a) The death rate is high
    b) The birth rate is high
    c) The literacy rate is high
    d) The economy is strong
    Answer: b) The birth rate is high
  90. Which woody raw material is used for the manufacture of paper pulp?
    a) Oak
    b) Poplar
    c) Pine
    d) Maple
    Answer: b) Poplar
  91. Rectified spirit contains alcohol about?
    a) 70%
    b) 85%
    c) 95%
    d) 100%
    Answer: c) 95%
  92. Which of the following elements is not present abundantly in Earth’s crust?
    a) Oxygen
    b) Silicon
    c) Radium
    d) Aluminum
    Answer: c) Radium
  93. The famous book; Al – Qanun was written by the Muslim scientist?
    a) Al-Biruni
    b) Abu Ali Sina
    c) Al-Khwarizmi
    d) Ibn al-Haytham
    Answer: b) Abu Ali Sina
  94. The primary source of energy for Earth’s climate system is?
    a) Geothermal energy
    b) Wind energy
    c) Solar energy
    d) Tidal energy
    Answer: c) Solar energy
  95. The hardest naturally occurring substance known is?
    a) Quartz
    b) Diamond
    c) Topaz
    d) Corundum
    Answer: b) Diamond
  96. The process by which plants lose water through leaves is called?
    a) Transpiration
    b) Evaporation
    c) Condensation
    d) Precipitation
    Answer: a) Transpiration
  97. The chemical symbol for gold is?
    a) Au
    b) Ag
    c) Cu
    d) Fe
    Answer: a) Au
  98. The largest organ in the human body is?
    a) Liver
    b) Skin
    c) Heart
    d) Lungs
    Answer: b) Skin
  99. The unit of measurement for the loudness of sound is?
    a) Hertz
    b) Decibel
    c) Watt
    d) Ampere
    Answer: b) Decibel
  100. The gas that makes up most of the Earth’s atmosphere is?
    a) Oxygen
    b) Nitrogen
    c) Carbon dioxide
    d) Argon
    Answer: b) Nitrogen
  101. The instrument used to measure atmospheric pressure is?
    a) Anemometer
    b) Barometer
    c) Hygrometer
    d) Thermometer
    Answer: b) Barometer
  102. The process of converting a solid directly into a gas is called?
    a) Melting
    b) Sublimation
    c) Condensation
    d) Freezing
    Answer: b) Sublimation
  103. The primary source of energy for the human body is?
    a) Proteins
    b) Carbohydrates
    c) Fats
    d) Vitamins
    Answer: b) Carbohydrates
  104. The planet with the most moons in our solar system is?
    a) Saturn
    b) Jupiter
    c) Uranus
    d) Neptune
    Answer: b) Jupiter
  105. The chemical process in which glucose is broken down to release energy in cells is called?
    a) Photosynthesis
    b) Respiration
    c) Fermentation
    d) Digestion
    Answer: b) Respiration
  106. The largest desert in the world is?
    a) Sahara
    b) Gobi
    c) Antarctic
    d) Arabian
    Answer: c) Antarctic
  107. The device used to measure electric current is?
    a) Voltmeter
    b) Ammeter
    c) Ohmmeter
    d) Galvanometer
    Answer: b) Ammeter
  108. The most abundant gas in the Earth’s atmosphere is?
    a) Oxygen
    b) Nitrogen
    c) Carbon dioxide
    d) Hydrogen
    Answer: b) Nitrogen
  109. The hormone that regulates blood sugar levels is?
    a) Insulin
    b) Adrenaline
    c) Thyroxine
    d) Estrogen
    Answer: a) Insulin
  110. The study of earthquakes is called?
    a) Seismology
    b) Volcanology
    c) Meteorology
    d) Oceanography
    Answer: a) Seismology
  111. The largest ocean on Earth is?
    a) Atlantic Ocean
    b) Indian Ocean
    c) Arctic Ocean
    d) Pacific Ocean
    Answer: d) Pacific Ocean
  112. The primary source of energy for Earth’s weather systems is?
    a) Geothermal heat
    b) Solar radiation
    c) Tidal forces
    d) Internal heat
    Answer: b) Solar radiation
  113. The element essential for making chlorophyll in plants is?
    a) Iron
    b) Magnesium
    c) Potassium
    d) Calcium
    Answer: b) Magnesium
  114. The device that converts sunlight into electricity is?
    a) Generator
    b) Solar cell
    c) Turbine
    d) Battery
    Answer: b) Solar cell
  115. The longest river in the world is?
    a) Nile
    b) Amazon
    c) Yangtze
    d) Mississippi
    Answer: b) Amazon
  116. The gas responsible for the green house effect is?
    a) Oxygen
    b) Carbon dioxide
    c) Nitrogen
    d) Hydrogen
    Answer: b) Carbon dioxide
  117. The part of the eye that controls the amount of light entering it is?
    a) Retina
    b) Cornea
    c) Iris
    d) Lens
    Answer: c) Iris
  118. The unit of power is?
    a) Joule
    b) Watt
    c) Volt
    d) Ohm
    Answer: b) Watt
  119. The process of turning liquid into vapor is called?
    a) Condensation
    b) Evaporation
    c) Freezing
    d) Melting
    Answer: b) Evaporation
  120. The largest planet in our solar system is?
    a) Earth
    b) Jupiter
    c) Saturn
    d) Uranus
    Answer: b) Jupiter

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