Samacheer Kalvi solutions for Science [English] Class 8 TN Board chapter 4 - Heat [Latest edition]

Fill in the blank

Heat is a form of _______.

If you apply some heat energy to a substance, which of the following can take place in it?

Which of the following substances will absorb more heat energy?

If you apply equal amount of heat to a solid, liquid, and gas individually, which of the following will have more expansion?

The process of converting a liquid into a solid is called ________.

Conduction is the way of heat transfer which takes place in a ______.

A calorimeter is a device used to measure the ______.

_______ is defined as the amount of heat required to raise the temperature of 1kg of a substance by 1°C.

A thermostat is a device which maintains _____.

The process of converting a substance from gaseous state to solid state is called _______.

If you apply heat energy, the temperature of a system will _____.

If the temperature of a liquid in a container is decreased, then the interatomic distance will ______.

The applied heat energy can be realized as an increase in the average kinetic energy of the molecules.

The dimensions of a substance are increased if the temperature of the substance is decreased.

The process of converting a substance from solid state to gaseous state is called condensation.

Convection is the process by which the thermal energy flows in solids.

The amount of heat gained by a substance is equal to the product of its mass and latent heat.

In a thermos flask, the silvered walls reflect and radiate the heat outside.

Match the following.

Consider the statement given below and choose the correct option.

Assertion: Radiation is a form of heat transfer which takes place only in vacuum.

Reason: The thermal energy is transferred from one part of a substance to another part without the actual movement of the atoms or molecules.

Consider the statement given below and choose the correct option.

Assertion: A system can be converted from one state to another state.

Reason: It takes place when the temperature of the system is constant.

What are the applications of conduction in our daily life?

What are the effects of heat?

Name three types of heat transfer.

What is conduction?

Write a note on convection.

Define specific heat capacity.

Define one calorie.

With the help of a neat diagram, explain the working of a calorimeter.

Write a note on thermostat.

Explain the working of thermos flask.

Why does the bottom of a lake not freeze in severe winter though the surface is all frozen?

Which one of the following statements about thermal conductivity is correct? Give reason.

Numerical Problems.

An iron ball requires 1000 J of heat to raise its temperature by 20°C. Calculate the heat capacity of the ball.

The heat capacity of the vessel of mass 100 kg is 8000 J/°K. Find its specific heat capacity.