What is Coefficient of Linear Expansion?

Linear expansion is the phenomenon of an increase in the length of a substance due to a temperature change. The coefficient of linear expansion (denoted as α) is a physical property that shows how much a material expands or contracts in length due to a change in temperature. It is an intrinsic property of a material and therefore, it is different for different materials.

• Coefficient of linear expansion measures how much a material expands per unit length.
• It is a constant value unique to each material.
• It is denoted by the symbol α.
• Different materials have different coefficients, depending on their molecular structure.

Coefficient of Linear Expansion Definition

Coefficient of Linear Expansion is defined as the rate of change in unit length per unit change in degree temperature is defined as the coefficient of linear expansion. 

Coefficient of Linear Expansion Formula

The rate of change of one unit length for every one-degree rise in temperature is known as the coefficient of linear expansion. Numerically, it can be expressed as:

α_L = ΔL/LΔT

where,

• L= initial length
• α_L = coefficient of linear expansion.
• ΔL= change in length
• ΔT= change in temperature

Dimension and S.I. units

The coefficient of linear expansion has dimensions of reciprocal temperature, typically in Kelvin. Its SI unit is Kelvin inverse (K^-1). This unit represents the change in length per unit length per degree Celsius.

• The linear expansion coefficient will have a dimension formula of [M⁰ L⁰ T⁰ K^-1].
• The S.I. unit of coefficient of linear expansion is °C^-1 or °K^-1 .

Coefficient of linear expansion is a constant that measures the change in a material’s length due to the temperature change. It is denoted by α. Every material has a unique coefficient of linear expansion. The unit of coefficient of linear expansion is K^-1.

In this article, we are going to learn about the Coefficient of Linear Expansion in detail, including its formula, applications, and a few solved examples based on it.