A steel rod of length 25 cm has a cross-sectional area of 0.8 cm2. The force required to stretch this rod by the same amount as the expansion produced by heating it through 10°C is (coefficient of linear expansion of steel is 10 51°C and Young’s modulus of steel is 2 × 1010 N/m2 ) …….
(a) 40 N
(b) 80 N
(c) 120 N
(d) 160 N
