Q101. At what temperature is the cryogenic test performed?
- A20°C
- B40°C
- C- 100°C
- D-196°C
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Answer: D) -196°C
Heat
179 MCQ questions with answers and explanations · page 5 of 8
Q102. Cryogenics is used in-
- Ain space travel, surgery, and magnetic resonance imaging
- Bin surgery, magnetic resonance imaging and telemetry
- Cin space travel, surgery and telemetry
- Din space travel, magnetic propagation and telemetry
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Answer: A) in space travel, surgery, and magnetic resonance imaging
Q103. The change of a solid substance directly into vapor state without changing into liquid is called-
- AKvdhan
- BDistillation
- CUplift
- DPolymerization
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Answer: C) Uplift
Q104. Sublimate substance is-
- AKapoor
- BNaphthalene
- Cammonium chloride
- DAll of the above
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Answer: D) All of the above
Q105. The temperature at which a solid substance changes into a liquid after receiving heat is called-
- ABoiling point
- BMelting point
- CEvaporation
- DNone of these
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Answer: B) Melting point
Q106. The temperature at which a liquid changes into vapour after receiving heat is called-
- AMelting point
- Bmelting point
- CBoiling point
- DNone of these
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Answer: C) Boiling point
Q107. What effect does evaporation have on the melting point of a pure substance when another substance is added to it?
- Aincreases
- Bhappens to
- Cremains unchanged
- Dfirst increases then decreases
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Answer: B) happens to
Q108. The melting point of alloys is higher than that of their constituent metals.
- AThe following are
- Bare high
- Care equal to
- DNone of these
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Answer: A) The following are
Q109. The change of state of matter from liquid to vapour is called-
- Amelting
- BEvaporation
- Cboiling
- DNone of these
Show answer & explanation
Answer: B) Evaporation
Q110. The change of state of matter from solid to liquid is called-
- Amelting
- BEvaporation
- Cboiling
- DNone of these
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Answer: A) melting
Q111. The boiling point of a liquid increases with increase in pressure.
- Awill decrease
- Bwill increase
- Cwill remain unchanged
- DSometimes it will decrease and sometimes it will increase
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Answer: B) will increase
Q112. What effect does the addition of impurities have on the melting point?
- Aincreases
- Bdecreases
- Cremains unchanged
- Dnone of these
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Answer: B) decreases
Q113. When does water boil?
- AWhen its vapor pressure is one gram per square cm.
- BWhen its vapour pressure is equal to 76 cm of mercury
- CThe potential vapor pressure of water is equal to the atmospheric pressure.
- DWhen the temperature of the water reaches 100°C
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Answer: C) The potential vapor pressure of water is equal to the atmospheric pressure.
Q114. The triple point of water is-
- A273.16°C
- B273.16°F
- C273.16K
- D373.16K
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Answer: C) 273.16K
Q115. The temperature of a liquid increases due to its vaporization.
- Awill increase
- Bwill decrease
- Cwill grow rapidly
- Dwill remain unchanged
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Answer: B) will decrease
Q116. The temperature at which ice, water and vapour remain in equilibrium is called—
- AFreezing point
- BBoiling point
- Ccritical temperature
- Dtriple point
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Answer: D) triple point
Q117. The rate of evaporation does not depend on-
- Aat the temperature of the liquid
- Bon the surface area of the liquid
- Cover the entire volume of the liquid
- Dat air pressure
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Answer: C) over the entire volume of the liquid
Q118. Where will it take longer to cook the rice?
- Aon the beach
- Bat the depths of the sea
- CIn Shimla
- Don Mount Everest
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Answer: D) on Mount Everest
Q119. The rate of evaporation for a given liquid depends on-
- Aat the temperature of the liquid
- Bat air temperature
- Cthe area of the open surface of the liquid
- Don all the above factors
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Answer: D) on all the above factors
Q120. Boiling Point of Water-
- Ais always 100°C
- Bdepends on the material of the container
- Cdepends on the relative humidity
- Ddepends on the pressure above the open surface of water
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Answer: D) depends on the pressure above the open surface of water
Q121. Why does it snow on high hills?
- ASome gas traps water vapor on high hills
- BClouds are close to the earth on hills, so water vapor freezes and turns into ice.
- COn high hills, the temperature is below freezing point, so water vapor freezes and turns into ice.
- Dnone of the above
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Answer: C) On high hills, the temperature is below freezing point, so water vapor freezes and turns into ice.
Q122. The reason why the snow covering the mountains does not melt all at once due to the heat of the sun is-
- AIt becomes very hard
- BIt reflects most of the heat received from the sun.
- CIt has a low specific heat capacity
- DIt has high latent heat of fusion
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Answer: B) It reflects most of the heat received from the sun.
Q123. Potatoes take more time to cook on mountain tops because-
- AThe temperature at the top of the mountain is lower than the temperature at sea level.
- BThe temperature is higher on the top of the mountain
- Catmospheric pressure is high
- Datmospheric pressure decreases
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Answer: D) atmospheric pressure decreases
Q124. Dew does not form on a windy night because-
- AThe rate of evaporation is faster
- BThere is less moisture in the air
- CThe temperature remains high
- DThe sky is not clear
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Answer: A) The rate of evaporation is faster
Q125. The process of preparing camphor vapour from solid camphor is called-
- Aevaporation
- Bfreezing
- Cmelt
- DUplift
Show answer & explanation
Answer: D) Uplift