question_answer

A bimetallic strip is formed out of two identical strips, one of copper and other of brass. The coefficients of linear expansion of the two metals are \[{{\alpha }_{C}}\]and \[{{\alpha }_{B}}\]. On heating the temperature of the strip goes up by AT and the strip bends to form an arc of radius of curvature R. Then R is

A) independent of \[\Delta T\]

B) independent of \[\Delta T\]

C) proportional to \[\left| {{\alpha }_{B}}-{{\alpha }_{C}} \right|\]

D) inversely proportional to \[\left| {{\alpha }_{B}}-{{\alpha }_{C}} \right|\]

Correct Answer: D

Solution :

Let  be the initial length of each strip before heating. Length after heating will be  and