PHYSICS [1 Mark Question Answer]

The water stored in the white sintex tank keeps cold because of less absorption and a good reflection of radiant heat from the white body.

The transfer of heat by radiation process does not require any medium. We prefer wearing dark-coloured clothes in winter because dark surfaces absorb more heat than light surfaces.

We prefer white coloured clothes in summer because white colour is poor absorber of heat and so they keep us cool during summer.

The marble floor which transmits heat energy easily feels colder and the carpet floor which does not allow heat to transmit feels warmer.

The sawdust or woolen blanket contains a large amount of trapped air, which acts as an insulator and does not allow the heat from outside to reach the ice.

Wood and plastic are bad conductors of heat. So, we can hold the pots with wooden or plastic handles directly, without burning our hands.

Thatched roof contains a large amount of trapped air. The heat from outside does not flow inside through the roofs because air is a bad conductor of heat. Thus the houses remain cool in summer.

Birds puff up their feathers in winter because by doing so they trap a large amount of air in their body which in turn acts as an insulator and does not allow the heat from their bodies to flow out.

We wear woolen clothes because they trap the bodies heat to keep us warm. On the other hand, thick and dark-coloured clothing is good in winter as it absorbs the sun’s rays to keeps us warm.

The materials which do not allow heat to pass through them easily are known as bad conductors. Examples: Glass, mica, ebonite, cotton, wool, etc.

The materials which allow heat to transfer through it easily are known as good conductors of heat. Examples: Silver, iron, copper, aluminum, etc.

A wooden chair feels not colder than an iron chair in winter.

The inner and outer surface of a vacuum flask are silvered.

Shining bodies are poor absorbers and poor radiators of heat energy.

Heat from the sun reaches the earth by the process of radiation.

Convection currents are not possible in solids.