# ICSE Class 9th Physics 5 – Heat and Energy MCQs

#### The flow of heat from one part of the body at higher temperature to another part of the same body at lower temperature is called conduction of heat.

Correct! Wrong!

The flow of heat from one part of the body at higher temperature to another part of the same body at lower temperature is called conduction of heat.

#### In which of the following transfer of heat takes place from the object to the surroundings?

Correct! Wrong!

Books and toys are at the same temperature of the surroundings, so there is no transfer of heat between them and the surroundings. The temperature of hot tea is more than its surroundings, so heat is transferred from tea to the surroundings.

#### The objects which do not allow the heat to pass through them are called ____.

Correct! Wrong!

The objects which do not allow the heat to pass through them are called insulators.

#### A motor converts electrical energy into ____.

Correct! Wrong!

A motor converts electrical energy into mechanical energy.

#### The transfer of heat by radiation does not require any medium.

Correct! Wrong!

The transfer of heat by radiation does not require any medium.

#### If we place one end of the copper rod in a flame while holding the other end, we feel that the temperature of the metal in our hand ____.

Correct! Wrong!

The end of the copper rod kept in the flame absorbs heat and its temperature increases. So, if we place one end of the copper rod in a flame while holding the other end, we feel that the temperature of the metal in our hand increases.

#### Natural gas mainly consists of ____.

Correct! Wrong!

Natural gas mainly consists of methane.

#### The cooking utensils are provided with copper bottoms in place of steel bottoms.

Correct! Wrong!

Copper is a good conductor of heat when compared to steel. The amount of heat supplied by copper bottom utensils is more compared to steel bottom in the same time. Cooking in copper bottom utensils will take less time, due to which fuel consumption is reduced. Hence, cooking utensils are provided with copper bottoms.

#### In a house ventilators are provided very near to the roof.

Correct! Wrong!

In the house ventilators are provided very near to the roof, because hot air rises up and escapes through them.

#### Convection of heat is not possible in liquids.

Correct! Wrong!

Convection of heat is possible in liquids. The process of heat transfer by the actual movement of the molecules is known as convection.

#### ____ is the fastest mode of transfer of heat.

Correct! Wrong!

Radiation is the fastest mode of transfer of heat because this mode does not require any medium for the heat transfer. The heat radiations travel with the speed of light; hence, radiation is the fastest mode of transfer of heat.

#### A student places four identical blocks of lead wrapped with black, blue, pale yellow and white cloths in sun light for same time duration. Which of the following attains maximum temperature?

Correct! Wrong!

Black surface is good absorber of heat compared to others. Hence, the block of lead wrapped with black cloth attains maximum temperature.

#### The vacuum in the thermos flask prevents loss of heat to the surroundings by ____.

Correct! Wrong!

Conduction and convection of heat require material medium for transfer of heat. Hence, vacuum in the thermos flask prevents loss of heat to the surroundings by conduction and convection.

#### Heating of water is due to ____.

Correct! Wrong!

Heating of water is due to convection. When the water is heated from the bottom, the molecules which are heated rise upwards while the molecules which are cold descend downwards to take its place. Thus, the convection currents are set up and the heating of water takes place throughout.

#### ____ is a renewable source of energy.

Correct! Wrong!

Tidal energy is a renewable source of energy. Coal, petroleum and natural gas are non-renewable sources of energy.

#### The heat received by a body due to radiation does not depend on the medium.

Correct! Wrong!

The heat received by a body due to radiation does not depend on the medium as this process of heat transfer does not require medium for its flow.

#### The mode of transfer of heat by the actual movement of molecules present in the medium is called convection of heat.

Correct! Wrong!

The mode of transfer of heat by the actual movement of molecules present in the medium is called convection of heat.

#### Transfer of heat from one place to another without affecting the medium is called radiation.

Correct! Wrong!

Transfer of heat from one place to another without affecting the medium is called radiation.

#### Beaker containing water and crystals of potassium permanganate is heated. The coloured water molecules ____.

Correct! Wrong!

When the water in the beaker is heated, the molecules which are heated rise upwards while the colder and the denser molecules move downwards. Hence, coloured water rises upwards.

#### An example of a good conductor is ____.

Correct! Wrong!

Lead is a metal, which is a good conductor of heat. Plastic, thermocol and saw dust are insulators of heat.

#### The land and sea breeze are convection currents.

Correct! Wrong!

Land breeze and sea breeze occurs due to the motion of hot air upwards and cold air moving down, to fill the space vacated by hot air, hence convection currents are set up.

#### Which of the following pair of energies does not create pollution?

Correct! Wrong!

Solar and wind energy does not create any pollution.

#### Mud houses remain cool during summers and warm in winters because, mud is ____ of heat.

Correct! Wrong!

Mud is a poor conductor of heat, so it prevents conduction of heat and hence, the houses remain cool during summers and warm in winters.

#### A wooden chair and a metallic chair are placed in sunlight for a long duration. If we are asked to sit on one of them, we will sit on the ____ chair because it is a ____ conductor of heat.

Correct! Wrong!

As both the chairs are in sunlight, for long duration the temperature will be same for both of them. If we sit on wooden chair we do not feel it very hot because being a bad conductor it does not transfer heat quickly. Hence, we sit on wooden chair, because it is a bad conductor of heat.

#### The solar energy received by each square meter of upper atmosphere of the earth per second is ____.

Correct! Wrong!

The solar energy received by each square meter of upper atmosphere of the earth per second is 1.36 kJ/s.

ICSE Class 9th Physics 5 - Heat and Energy MCQs
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