A Journey through States of Water Part 3: MCQs (Q51–Q75)
Part 3 — Questions 51 to 75 (Water cycle, daily life examples, cooling effect)
51. The process of water changing into vapor from leaves of plants is called
A. Evaporation
B. Condensation
C. Transpiration ← Correct Answer
D. Freezing
Explanation:
C) Correct — plants lose water vapor through stomata in leaves.
52. Which process is used by plants to add water vapor into the atmosphere?
A. Photosynthesis
B. Transpiration ← Correct Answer
C. Condensation
D. Respiration
Explanation:
B) Correct — transpiration releases moisture into the air.
53. Water vapor rises into the atmosphere mainly due to
A. Freezing
B. Evaporation and transpiration ← Correct Answer
C. Condensation
D. Precipitation
Explanation:
B) Correct — evaporation from surfaces + transpiration from plants.
54. Rain is an example of
A. Evaporation
B. Precipitation ← Correct Answer
C. Sublimation
D. Fusion
Explanation:
B) Correct — condensed water droplets fall as rain.
55. The cooling effect during evaporation occurs because
A. Air becomes cold
B. Liquid absorbs heat from surroundings to change into vapor ← Correct Answer
C. Vapor is cold
D. Heat disappears
Explanation:
B) Correct — heat absorbed lowers temperature of surroundings.
56. Which of these best describes condensation?
A. Gas → liquid ← Correct Answer
B. Solid → gas
C. Liquid → gas
D. Solid → liquid
Explanation:
A) Correct — vapor turns back into liquid.
57. Clothes dry faster on a windy day because
A. Wind warms them
B. Wind carries away vapor, speeding evaporation ← Correct Answer
C. Air is heavier
D. Water melts
Explanation:
B) Correct — evaporation is faster with airflow.
58. Which of these is NOT an example of evaporation?
A. Clothes drying
B. Cloud formation ← Correct Answer
C. Cooling of water in earthen pot
D. Sweat drying
Explanation:
B) Correct — clouds form by condensation, not evaporation.
59. Sea water is salty because
A. Salt dissolves in rain
B. Evaporation leaves salts behind ← Correct Answer
C. Ocean floor is salty
D. Fish add salt
Explanation:
B) Correct — evaporation removes pure water, salts remain.
60. Salt is obtained from sea water by
A. Condensation
B. Evaporation ← Correct Answer
C. Freezing
D. Filtration
Explanation:
B) Correct — evaporation leaves solid salt behind.
61. Which step of water cycle purifies water naturally?
A. Precipitation
B. Evaporation ← Correct Answer
C. Freezing
D. Runoff
Explanation:
B) Correct — only water vapor rises, leaving impurities behind.
62. Clouds bring rain due to
A. Condensation of vapor forming heavy droplets ← Correct Answer
B. Freezing of rivers
C. Melting glaciers only
D. Sea tides
Explanation:
A) Correct — water vapor condenses to rain droplets.
63. Which is an example of freezing in nature?
A. Formation of snow in mountains ← Correct Answer
B. Cloud formation
C. Drying of clothes
D. Steam rising
Explanation:
A) Correct — liquid water freezes into snow.
64. Which shows sublimation in daily life?
A. Naphthalene balls disappearing ← Correct Answer
B. Ice melting
C. Water freezing
D. Steam condensing
Explanation:
A) Correct — naphthalene sublimes solid → gas.
65. Why does sweating cool the body?
A. Sweat is cold
B. Sweat evaporates, absorbing heat from skin ← Correct Answer
C. Air cools sweat
D. Sweat condenses
Explanation:
B) Correct — evaporation uses body heat, cooling effect.
66. Which process in the water cycle directly adds water vapor from oceans into air?
A. Condensation
B. Evaporation ← Correct Answer
C. Precipitation
D. Freezing
Explanation:
B) Correct — water evaporates from oceans into atmosphere.
67. Which process removes water vapor from atmosphere?
A. Evaporation
B. Condensation (clouds, rain) ← Correct Answer
C. Transpiration
D. Melting
Explanation:
B) Correct — vapor condenses to liquid/solid.
68. Frost formation on leaves during winter mornings is due to
A. Condensation followed by freezing ← Correct Answer
B. Evaporation
C. Melting
D. Sublimation
Explanation:
A) Correct — vapor condenses then freezes.
69. Which change involves latent heat of fusion?
A. Melting ice to water ← Correct Answer
B. Boiling water
C. Evaporation
D. Condensation
Explanation:
A) Correct — fusion = solid ↔ liquid at constant temp.
70. Which change involves latent heat of vaporization?
A. Freezing water
B. Boiling water to steam ← Correct Answer
C. Melting ice
D. Condensation
Explanation:
B) Correct — vaporization at constant temp uses latent heat.
71. Which factor does NOT affect evaporation?
A. Surface area
B. Temperature
C. Wind
D. Color of liquid ← Correct Answer
Explanation:
D) Correct — evaporation not affected by color, but by heat, wind, surface area.
72. Which natural process purifies seawater into rainwater?
A. Freezing
B. Evaporation + condensation ← Correct Answer
C. Filtration
D. Sedimentation
Explanation:
B) Correct — water cycle removes impurities.
73. What is the main source of energy driving the water cycle?
A. Moon
B. Stars
C. Sun ← Correct Answer
D. Wind
Explanation:
C) Correct — sunlight causes evaporation.
74. Which water change is used in making jaggery crystals?
A. Freezing
B. Evaporation ← Correct Answer
C. Condensation
D. Melting
Explanation:
B) Correct — boiling off water leaves crystals behind.
75. Why do deserts have faster drying of clothes?
A. Low wind
B. High temperature and low humidity ← Correct Answer
C. No sun
D. Cold air
Explanation:
B) Correct — heat + dry air accelerate evaporation.
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