A steel rod of dimesions 4 `xx 4 cm^(2)` is tightly fixed between two supports and is not allowed to expand. It is heated through `2^(@) `C. Thermal stress developed is .... `10^(6) N//m^(2)`

Options

A. 7.2
B. 2.7
C. 3.6
D. 0.72

Answer

A