A steel rod of length `1 m` is heated from `25^@ "to" 75^@ C` keeping its length constant. The longitudinal strain developed in the rod is ( Given, coefficient of linear expansion of steel = `12 xx 10^-6//^@ C`).

Options

A. `6 xx10^(-6)`
B. `-6 xx 10^(-5)`
C. `-6 xx 10^(-4)`
D. zero

Answer

C

Explanation

Strain
` t=(Deltal)/(l) = -alphaDeltatheta= -12 xx 10^(-6) xx (75-25) = -6 xx 10^(-4)`