General Knowledge MCQs (page 32 of 61)
Famous people, inventions, sports, world records, currencies and well-known facts about Pakistan and the world.
1,204 questions. Select an option to check your answer, or open "Show answer". Showing 621–640.
- 621.
Beriberi is caused by the deficiency of:
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Answer: A. Vitamin B1 (Thiamine)
It affects the nerves and heart.
- 622.
Night blindness is caused by the deficiency of:
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Answer: A. Vitamin A
Vitamin A is needed for vision in dim light.
- 623.
Scurvy is caused by the deficiency of:
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Answer: B. Vitamin C
It causes bleeding gums.
- 624.
Which vitamin is produced in the skin by sunlight?
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Answer: C. Vitamin D
It helps the body absorb calcium.
- 625.
The pH of pure water is:
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Answer: C. 7
A pH of 7 is neutral.
- 626.
Which metal is liquid at room temperature?
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Answer: D. Mercury
Its symbol is Hg.
- 627.
The lightest element is:
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Answer: A. Hydrogen
It has atomic number 1.
- 628.
The chemical symbol of iron is:
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Answer: D. Fe
It comes from the Latin word "ferrum".
- 629.
The chemical symbol of sodium is:
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Answer: A. Na
It comes from the Latin word "natrium".
- 630.
The chemical symbol of gold is:
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Answer: B. Au
It comes from the Latin word "aurum".
- 631.
The ozone layer is mainly depleted by:
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Answer: D. Chlorofluorocarbons (CFCs)
The Montreal Protocol (1987) phased out CFCs.
- 632.
The ozone layer is found in the:
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Answer: C. Stratosphere
It absorbs harmful ultraviolet rays.
- 633.
The most abundant gas in Earth's atmosphere is:
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Answer: B. Nitrogen
Nitrogen makes up about 78% of air.
- 634.
The chemical formula of common salt is:
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Answer: C. NaCl
Its chemical name is sodium chloride.
- 635.
The hardest natural substance is:
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Answer: B. Diamond
It is a form of pure carbon.
- 636.
Sound cannot travel through:
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Answer: B. Vacuum
Sound needs a medium to travel.
- 637.
The speed of light in vacuum is about:
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Answer: C. 3 × 10⁸ m/s
That is roughly 300,000 km per second.
- 638.
The SI unit of frequency is:
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Answer: C. Hertz
One hertz is one cycle per second.
- 639.
The SI unit of electrical resistance is:
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Answer: B. Ohm
It is named after Georg Simon Ohm.
- 640.
The SI unit of power is:
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Answer: C. Watt
One watt equals one joule per second.