Heat is a form of energy which is transferred from a substance having higher temperature to a substance having lower temperature. Addition of heat to a substance increases its internal temperature. No matter if it is a volcano or an ice cube, it has some amount of heat.

Green colored surface is good radiator. As we know, Good absorber is good raditor, so here green color is good absorber of heat as compare to silver color.

Energy from the sun comes to us by radiation. Heat transfer through conduction is a slow process. Radiation is the fastest because in this case, the transfer of heat takes place at the speed of light. Both conduction and convection need a material medium for the transfer for heat.

(b) The temperature varies with distance along the insulated bar (c) Temperature does not vary linearly along the length 0 bar. The rate of fall of temperature with distance in the direction of heat flow is called the temperature gradient. The temperature gradient of the rod is uniform.

Convection is the transfer of heat energy through the movement of fluid particles. Hence, convection cannot take place in solids, since the solid particles are not fluid. Thus, convection only takes place in liquids and gases.

Convection is the transfer of heat by the physical movement of hot masses of air. Soon a convection column is formed above the fire which can be seen by the smoke that is carried aloft in it. This in-draft of cooler air from the side helps to supply additional oxygen for the combustion process to continue.

Temperature