With an illustration, explain the method of calculation for areal expansion of an object.

Explanation

• If there is an increase in the area of a solid object due to heating, then the expansion is called superficial or arcal expansion.
• Superficial expansion is determined in terms of coefficient of superficial expansion. The ratio of increase in area of the body per degree rise in temperature to its unit area is called as coefficient of superficial expansion. Coefficient of superficial expansion is different for different materials. The si superficial expansion unit of Coefficient of superficial expansion is K
• The equation relating to the change in area and the change in temperature

`(DeltaA)/(A_(0))=alpha_(A)DeltaT`
`DeltaA`- Change in area (Final area - Initial area)
`A_(0)` - Original area
`DeltaT` - Change in temperature (Final temperature - Initial temperature)
`alpha_(A)`- Coefficient of superficial expansion.