A steel wire of length 20 cm and area of cross-section 1 mm2 is tied rigidly at both the ends. When the temperature of the wire is changed from 400C to 200C, find the change in its tension. Given, the coefficient of linear expansion for steel is 1.1×10−5 0C−1 and Young’s modulus of steel is 2.0×1011Nm−2.