Question

The coefficient of superficial expansion of a solid is twice the linear expansion coefficient of the same solid.

• A. True
• B. False

Answer 1

The correct option is A True

1. When a metal rod is heated its length increases this is called linear expansion.
2. The coefficient of linear expansion$\left(\mathrm{\alpha }\right)$ of the material of a solid rod or wire is defined as the increase in its length per unit of original length per degree rise in temperature.
3. When a metallic sheet is heated, its surface area increases this is called the superficial or area expansion.
4. The coefficient of superficial expansion$\left(\mathrm{\beta }\right)$ of the material of a solid thin sheet is defined as the increase in its surface area per unit of original surface area per degree rise in temperature.
5. It is observed that for a given material the value of the coefficient of area expansion is twice the coefficient of linear expansion of that material.
6. That is $\mathrm{\beta }=2\mathrm{\alpha }$

thus, the given statement is true.