ISSB - PAF Officer Selection General Knowledge Science — Set 3

Science MCQs set 3 for ISSB - PAF Officer Selection General Knowledge — 20 solved questions.

ISSB - PAF Officer Selection General Knowledge Science — Set 3

  1. Question 1

    Q1. Which gas is used by plants in photosynthesis?

    • A) Oxygen
    • B) Carbon dioxide
    • C) Nitrogen
    • D) Hydrogen

    Answer: Carbon dioxide

    Explanation: Plants absorb carbon dioxide during photosynthesis. This fact often appears in ISSB academic and general knowledge sections.

  2. Question 2

    Q2. The chemical symbol for sodium is:

    • A) S
    • B) Na
    • C) So
    • D) Sd

    Answer: Na

    Explanation: Sodium has the symbol Na from the Latin natrium. This fact often appears in ISSB academic and general knowledge sections.

  3. Question 3

    Q3. The speed of light is about:

    • A) 300,000 km/s
    • B) 300 km/s
    • C) 3,000 km/s
    • D) 30,000 km/s

    Answer: 300,000 km/s

    Explanation: Light travels about 300,000 km per second in vacuum. This fact often appears in ISSB academic and general knowledge sections.

  4. Question 4

    Q4. The human adult skeleton has about:

    • A) 106 bones
    • B) 206 bones
    • C) 306 bones
    • D) 406 bones

    Answer: 206 bones

    Explanation: An adult human has about 206 bones. This fact often appears in ISSB academic and general knowledge sections.

  5. Question 5

    Q5. SI unit of energy is:

    • A) Newton
    • B) Joule
    • C) Watt
    • D) Pascal

    Answer: Joule

    Explanation: Energy is measured in joules in the SI system. This fact often appears in ISSB academic and general knowledge sections.

  6. Question 6

    Q6. The chemical symbol for iron is:

    • A) Ir
    • B) Fe
    • C) In
    • D) I

    Answer: Fe

    Explanation: Iron has the symbol Fe from the Latin ferrum. This fact often appears in ISSB academic and general knowledge sections.

  7. Question 7

    Q7. The process by which plants make food is:

    • A) Respiration
    • B) Photosynthesis
    • C) Digestion
    • D) Fermentation

    Answer: Photosynthesis

    Explanation: Photosynthesis is how plants make food using light. This fact often appears in ISSB academic and general knowledge sections.

  8. Question 8

    Q8. The boiling point of water at sea level is:

    • A) 90°C
    • B) 100°C
    • C) 110°C
    • D) 120°C

    Answer: 100°C

    Explanation: Water boils at 100 degrees Celsius at standard pressure. This fact often appears in ISSB academic and general knowledge sections.

  9. Question 9

    Q9. The human heart has how many chambers?

    • A) 2
    • B) 3
    • C) 4
    • D) 5

    Answer: 4

    Explanation: The human heart has four chambers. This fact often appears in ISSB academic and general knowledge sections.

  10. Question 10

    Q10. The chemical formula of carbon dioxide is:

    • A) CO
    • B) CO2
    • C) C2O
    • D) O2

    Answer: CO2

    Explanation: Carbon dioxide is CO2. This option matches the rule tested here. Work each step carefully; ISSB math rewards accuracy under time pressure.

  11. Question 11

    Q11. Vitamin D is mainly produced by:

    • A) Darkness
    • B) Sunlight on skin
    • C) Only food always
    • D) Only water

    Answer: Sunlight on skin

    Explanation: Sunlight helps the skin produce vitamin D. This fact often appears in ISSB academic and general knowledge sections.

  12. Question 12

    Q12. Adult human bones number about:

    • A) 106
    • B) 206
    • C) 306
    • D) 406

    Answer: 206

    Explanation: An adult human skeleton has about 206 bones. This fact often appears in ISSB academic and general knowledge sections.

  13. Question 13

    Q13. Speed of light in vacuum is approximately?

    • A) 3×10⁸ m/s
    • B) 3×10⁶ m/s
    • C) 3×10¹⁰ m/s
    • D) 3×10⁴ m/s

    Answer: 3×10⁸ m/s

    Explanation: Light travels about three hundred million meters per second in vacuum. Work each step carefully; ISSB math rewards accuracy under time pressure.

  14. Question 14

    Q14. Human body normal temperature is about?

    • A) 96°F
    • B) 98.6°F
    • C) 100°F
    • D) 102°F

    Answer: 98.6°F

    Explanation: Normal body temperature is approximately 98.6 degrees Fahrenheit. This fact often appears in ISSB academic and general knowledge sections.

  15. Question 15

    Q15. Gas essential for respiration?

    • A) Nitrogen
    • B) Oxygen
    • C) Carbon dioxide
    • D) Hydrogen

    Answer: Oxygen

    Explanation: Humans breathe in oxygen for cellular respiration. This fact often appears in ISSB academic and general knowledge sections.

  16. Question 16

    Q16. Planet closest to the Sun?

    • A) Venus
    • B) Mercury
    • C) Earth
    • D) Mars

    Answer: Mercury

    Explanation: Mercury is the innermost planet in our solar system. This fact often appears in ISSB academic and general knowledge sections.

  17. Question 17

    Q17. Vitamin from sunlight on skin?

    • A) Vitamin A
    • B) Vitamin C
    • C) Vitamin D
    • D) Vitamin K

    Answer: Vitamin D

    Explanation: Skin produces vitamin D when exposed to sunlight. This fact often appears in ISSB academic and general knowledge sections.

  18. Question 18

    Q18. Boiling point of water at sea level?

    • A) 90°C
    • B) 100°C
    • C) 110°C
    • D) 120°C

    Answer: 100°C

    Explanation: Water boils at 100 degrees Celsius at standard pressure. This fact often appears in ISSB academic and general knowledge sections.

  19. Question 19

    Q19. Blood cells that fight infection?

    • A) Red blood cells
    • B) White blood cells
    • C) Platelets
    • D) Plasma only

    Answer: White blood cells

    Explanation: White blood cells are part of the immune defense. This fact often appears in ISSB academic and general knowledge sections.

  20. Question 20

    Q20. SI unit of force?

    • A) Joule
    • B) Newton
    • C) Watt
    • D) Pascal

    Answer: Newton

    Explanation: Force is measured in newtons in the SI system. This fact often appears in ISSB academic and general knowledge sections.