A steel rod with a cross sectional area of `150 mm^2` is streched between two fixed points. The tensile load at `20^@C` is 5000 N. The stress in rod at - `20^@C` is `n xx 25 xx 10^6 N//m^2`. What is the value of n ? (Assume, `alpha=11.5 xx 10^(-6)//^@C` and `y= 200 xx 10^11 N//m^2`)

Answer

5