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

Answer

C

Explanation

Strain developed:
`epsilon = alpha Delta T = (12 xx 10^(-6))(50)=6 xx 10^(-4)`
Strain will be negative, as the rod is in a compressed state.