CBSE Class 7 Answered

What is heat?write its types.

Asked by amitk8298 | 23 Mar, 2019, 01:00: PM

Expert Answer

Heat energy, also called thermal energy or simply heat, is energy transferred from one object to other object.

If we consider heat is the energy flow, then this energy flow is from object at high temperature to other object at lower temperature.

Temperature of the object is a measure of thermal energy content in the object.

There are three types of flow of heat energy or heat transfer, i.e., conduction, convection and radiation.

In conduction process, objects are in physcal contact and heat enrgy flows from high temperature region to lower temperature region.

Convection occurs in liquids and gases. High temperature region has low density and low temperature region has high density.

Due to this density difference there is flow of liquid/gas from low temeprature region to high temeperature region and energy transfer is taking place.

At very high temperature, in absence of physical contact and relative movement of objects, heat energy transfer is taking place by radiation.
High temperature object emits infre-red rays and heating the surrounding or other object.

Answered by Thiyagarajan K | 23 Mar, 2019, 02:12: PM