Question

Explain thermal expansion and its types.

Answer 1

Thermal expansion:

1. Thermal expansion is the phenomenon observed in solids, liquids, and gases.
2. In this process, an object or body expands on the application of heat (temperature).
3. Thermal expansion defines the tendency of an object to change its dimension either in length, density, area, or volume due to heat.
4. Gases expand much more than liquids and liquids expand much more than solids for a given rise in temperature.

Types of thermal expansion:

There are three types of thermal expansion, i.e., Linear expansion, area (superficial) expansion, and volume expansion.

1. Linear expansion - It is a type of thermal expansion in which the length of the solid increases when it is heated. This type of thermal expansion occurs in a rod or wire.
2. Area (Superficial expansion) - If the solid is in the form of a thin sheet, then its surface area increases on heating, and this type of thermal expansion is known as superficial expansion.
3. Volume expansion - When a solid such as a cube, sphere, cuboid, or cylinder is heated, its volume increases and this type of thermal expansion is known as volume expansion.