# ICSE Class 10th Physics 5 – Heat MCQs

#### Statement A: During winter, a farmer waters his crops during the evening, to prevent damage to the crop from frost. Statement B: Water has high specific heat capacity. State which statement/s is true.

Correct! Wrong!

Statement A: During winter, a farmer waters his crops during the evening, to prevent damage of the crop from frost. Statement B: Water has high specific heat capacity Water has very high specific heat capacity. In winter season, it is advisable to water the crops in the evening time. The water given to the crops liberates enough heat during the night in the process of cooling down, because of its very high specific heat capacity. This prevents damage to the crop from frost. Hence, both A and B are true.

#### Which of the following substances sublime?

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Solid carbon dioxide or dry ice sublimes when exposed to atmosphere.

#### Latent heat is ____.

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Latent heat is defined as the amount of heat required to change the state of 1 kg of a substance.

#### The process involved in drying wet clothes is ____

Correct! Wrong!

The water in wet clothes evaporates while drying.

#### Choose the correct statement among the following.

Correct! Wrong!

The rate of evaporation increases with increase in temperature. Higher the temperature faster is the rate of evaporation.

#### In the given options, during change of state of a substance, the physical quantities associated with the substance, that are not constant are____.

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During change of state of a substance, the physical quantities associated with the substance that are not constant are both volume and density. Theses change with change in state.

#### Which of the following statements is correct?

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Matter can change states when temperature and pressure are altered.

#### In the process of freezing ____.

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The process of changing of a liquid to solid by cooling is called freezing.

#### Solid carbon dioxide is stored under ____.

Correct! Wrong!

Solid carbon dioxide is stored under high pressure and low tem

#### If the pressure is increased the boiling point of water ____.

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Increase in pressure, increases the boiling point of water as boiling point is the temperature at which the vapour pressure of the liquid becomes equal to the atmospheric pressure.

#### The specific heat capacity of a substance depends on ____.

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The specific heat capacity of a substance depends on its nature and temperature. The specific heat capacity of a substance depends on the nature of material and its temperature.

#### Sublimation is change of state directly from ____.

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Sublimation is a process in which, a solid directly changes into gas without changing into liquid when there is a change in temperature.

#### LPG is filled in domestic gas cylinders by compressing it at ____.

Correct! Wrong!

LPG is filled in domestic gas cylinders by compressing it at high pressure and low temperature.

#### The principle of mixtures is a direct consequence of the law of conservation of ____.

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The principle of mixtures is a direct consequence of the law of conservation of energy. Law of conservation of energy is the basis for the principle of mixtures, since heat is only exchanged between the contents of the mixture.

#### When a gas condenses to a liquid, the intermolecular forces of attraction between the molecules ____.

Correct! Wrong!

When the gas condenses into a liquid, the intermolecular forces of attraction between the molecules increases.

#### When salt is added to water, then its boiling point ____.

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When salt is added to water, the boiling point increases, since, presence of impurities in a substance increases its boiling point.

#### When vaporization takes place, then ____.

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When vaporization takes place, the force of attraction between the particles of a liquid decreases and it changes to gaseous phase.

#### The value of boiling point of water in kelvin scale is ____.

Correct! Wrong!

Temperature in kelvin scale = Temperature in celsius scale + 273 = 100 + 273 = 373 K The value of boiling point of water in kelvin scale is 373 K.

#### Which of the following factors effect evaporation?

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The rate of evaporation depends on the surface area and also temperature.

Correct! Wrong!

#### he heat required to convert ice of mass 2 kg at (-10°C) to water at 100 °C is ____joule. Take the specific heat capacity of ice as 2100 J kg-1°C-1, specific heat capacity of water as 4186 J kg-1 °C-1 and latent heat of fusion of ice as 3.35 × 105 J kg-1.A. 1249200

Correct! Wrong!

The heat required to convert ice of mass 2 kg at (-10 °C) to water at 100 °C is 1549200 joule. Given, mass of ice m = 2 kg Initial temperature of the ice = (-10 °C) To raise from (-10 °C) to water at (100°C) the quantity of heat required is Q = msi(0 - (-10) + mLf + msw (100 - 0) -------> (1) In the equation 1, msi (0 - (-10) is the heat required to raise the ice from (-10°C) to 0 °C mL f is the heat required to convert ice at 0 °C to water at 0°C and msw (100 - 0) is the heat required to raise the temperature of water from 0 °C to 100 °C. Therefore, Q = 2((2100 × 10) + (3.35 × 105) + (4186 × 100) Q = 200 (210 + 3350 + 4186) Q = 1549200 J

#### A wet cloth is placed on the forehead of a person having high temperature, because ____.

Correct! Wrong!

The water of the wet cloth placed on the forehead evaporates absorbing the heat from the body, hence, it is advised to place a wet cloth on the forehead of a person having high temperature.

#### Which is more dangerous to skin?

Correct! Wrong!

Steam is more dangerous to skin than boiling water. Steam has an instantaneous effect of burning into skin due to latent heat of vaporization.

#### When glaciers melt, they start melting from the bottom. This is due to the fact that,____.

Correct! Wrong!

When glaciers melt, they start melting from the bottom. This is due to the fact that, the melting point of ice is lowered with increase in pressure.

#### In the process of melting, ____.

Correct! Wrong!

Melting is a process in which solid changes to liquid by absorbing heat.

ICSE Class 10th Physics 5 - Heat MCQs
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