A Journey through States of Water Part 4: MCQs (Q76–Q100)
Part 4 — Questions 76 to 100 (Revision, applications, environment)
76. Which process is responsible for formation of rain?
A. Evaporation
B. Condensation ← Correct Answer
C. Freezing
D. Melting
Explanation:
B) Correct — vapor condenses into droplets, leading to rain.
77. Clouds floating in the sky are made up of
A. Pure vapor
B. Tiny droplets and ice crystals ← Correct Answer
C. Smoke particles only
D. Hot air
Explanation:
B) Correct — clouds = condensed water droplets or ice.
78. Which of the following is an example of sublimation?
A. Ice melting
B. Water freezing
C. Dry ice changing into CO₂ gas ← Correct Answer
D. Dew formation
Explanation:
C) Correct — dry ice sublimes directly into gas.
79. Which step in water cycle causes formation of glaciers?
A. Condensation
B. Freezing of water into ice ← Correct Answer
C. Sublimation
D. Evaporation
Explanation:
B) Correct — frozen water collects as glaciers.
80. Which of these is a reversible change?
A. Cooking food
B. Burning candle wick
C. Melting of ice ← Correct Answer
D. Rusting of iron
Explanation:
C) Correct — ice can be refrozen.
81. Which state of water has fixed volume but no fixed shape?
A. Solid
B. Liquid ← Correct Answer
C. Gas
D. Plasma
Explanation:
B) Correct — liquids take container’s shape but keep volume.
82. Which state of water spreads and fills any container?
A. Solid
B. Liquid
C. Gas ← Correct Answer
D. Plasma
Explanation:
C) Correct — gases expand to fill full space.
83. Why does water form droplets on the outer side of a cold glass?
A. Evaporation
B. Condensation of air moisture ← Correct Answer
C. Freezing
D. Melting
Explanation:
B) Correct — vapor condenses on cold surface.
84. Which of these is NOT a state of water?
A. Ice
B. Steam
C. Snow
D. Fog ← Correct Answer
Explanation:
D) Correct — fog is suspension of tiny droplets, not a fundamental state.
85. Which change is shown when camphor disappears on heating?
A. Condensation
B. Sublimation ← Correct Answer
C. Freezing
D. Melting
Explanation:
B) Correct — camphor sublimes directly into vapor.
86. Which step of the water cycle involves plants?
A. Condensation
B. Precipitation
C. Transpiration ← Correct Answer
D. Evaporation
Explanation:
C) Correct — plants release water vapor via transpiration.
87. Which natural phenomenon maintains balance of water on Earth?
A. Photosynthesis
B. Respiration
C. Water cycle ← Correct Answer
D. Soil erosion
Explanation:
C) Correct — cycle maintains balance among oceans, atmosphere, land.
88. Which factor makes evaporation fastest?
A. Cold weather, humid
B. Hot, dry, windy conditions ← Correct Answer
C. No wind, humid
D. Dark room
Explanation:
B) Correct — heat + dryness + wind speed up evaporation.
89. Which change occurs when steam turns into water droplets on a lid?
A. Freezing
B. Condensation ← Correct Answer
C. Evaporation
D. Sublimation
Explanation:
B) Correct — gas → liquid.
90. Rainwater harvesting mainly helps in
A. Making lakes dirty
B. Recharging groundwater ← Correct Answer
C. Melting glaciers
D. Producing salt
Explanation:
B) Correct — collected rain seeps into soil to recharge wells.
91. Which is an irreversible change?
A. Boiling egg ← Correct Answer
B. Melting ice
C. Condensation
D. Freezing
Explanation:
A) Correct — egg can’t return to raw form.
92. Fog and mist are examples of
A. Evaporation
B. Condensation near the ground ← Correct Answer
C. Sublimation
D. Freezing
Explanation:
B) Correct — condensed tiny droplets form fog/mist.
93. Steam at 100°C has more heat energy than boiling water at 100°C because
A. Steam is lighter
B. It contains latent heat of vaporization ← Correct Answer
C. Steam is visible
D. Boiling water is cooler
Explanation:
B) Correct — extra energy makes steam burns severe.
94. Clouds are formed because warm air
A. Falls down
B. Cools, and water vapor condenses ← Correct Answer
C. Absorbs sunlight
D. Freezes instantly
Explanation:
B) Correct — cooling causes condensation, forming clouds.
95. Which process is used in making salt from sea water?
A. Filtration
B. Evaporation ← Correct Answer
C. Freezing
D. Condensation
Explanation:
B) Correct — evaporating water leaves salt crystals.
96. What type of change is boiling water into steam?
A. Chemical change
B. Physical change ← Correct Answer
C. Irreversible change
D. New substance formed
Explanation:
B) Correct — no new substance formed, reversible.
97. Which change happens when frost appears on ground?
A. Melting
B. Condensation + freezing ← Correct Answer
C. Evaporation
D. Sublimation
Explanation:
B) Correct — vapor condenses, then freezes.
98. Which form of water has maximum energy?
A. Ice
B. Liquid water
C. Steam (gas) ← Correct Answer
D. Snow
Explanation:
C) Correct — particles in gas move fastest.
99. Which process adds fresh water to land naturally?
A. Evaporation
B. Precipitation (rain, snow) ← Correct Answer
C. Sublimation
D. Melting
Explanation:
B) Correct — precipitation delivers water to Earth’s surface.
100. Final quick revision: Which statement is correct?
A. Evaporation = gas → liquid
B. Condensation = liquid → gas
C. Freezing = solid → liquid
D. Melting = solid → liquid, Freezing = liquid → solid, Condensation = gas → liquid ← Correct Answer
Explanation:
D) Correct — matches actual processes.
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