Question

A composite rod is made of copper $\alpha =1.8\times {10}^{-5}{K}^{-1}$ and steel $1.2\times {10}^{-5}{K}^{-1}$ as shown in figure, is heated up, then it

• A. $\text{bends with steel on concave side}$
• B. $\text{bends with copper on concave side}$
• C. $\text{dose not expand}$
• D. $\text{data is insufficient}$

Answer 1

The correct option is A $\text{bends with steel on concave side}$


When a bimetallic strip is heated, it bends with metal of lesser $\alpha$ on inner side, i.e concave side.