MCQ Collection
CSS MCQs
Practice CSS questions with answers and explanations.
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Correct Answer: B. Evaporation removes heat from the skin
Explanation:
The highest-energy water molecules escape during evaporation.
This lowers the average energy and temperature of the skin.
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Correct Answer: B. violet
Explanation:
Violet light has the shortest wavelength among visible colors.
It also has the highest visible-light frequency.
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Correct Answer: C. Moving air removes humid air near the clothes
Explanation:
Wind carries away water vapor near the fabric.
This maintains a concentration difference and speeds evaporation.
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Correct Answer: C. Shorter blue wavelengths are scattered more strongly by air
Explanation:
Rayleigh scattering is stronger for shorter visible wavelengths.
Scattered blue light reaches observers from many directions.
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Correct Answer: D. Rapid vaporization throughout a liquid
Explanation:
At boiling, vapor bubbles form throughout the liquid.
It occurs when vapor pressure matches external pressure.
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Correct Answer: D. Blue light is scattered out over the longer atmospheric path
Explanation:
Sunlight travels through more atmosphere near the horizon.
Much of the shorter-wavelength light is scattered away.
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Correct Answer: A. A lower temperature
Explanation:
Atmospheric pressure decreases with altitude.
Lower pressure allows water to boil at a lower temperature.
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Correct Answer: A. A mechanical wave produced by vibrations
Explanation:
Sound begins with vibrating matter.
It travels through a medium as pressure variations.
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Correct Answer: B. Water boils at a lower temperature
Explanation:
Boiling water is cooler at high altitude.
The lower cooking temperature slows many cooking processes.
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Correct Answer: B. No
Explanation:
Sound requires particles to transmit vibrations.
A vacuum contains too few particles for sound propagation.
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Correct Answer: C. radiation
Explanation:
Thermal radiation travels as electromagnetic waves.
It does not require a material medium.
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Correct Answer: C. Higher pressure raises water's boiling point
Explanation:
Pressure inside the cooker increases above atmospheric pressure.
Water then boils at a higher temperature and cooks food faster.