question_answer

A steel wire of length 20 cm and uniform cross- section \[1\,\,m{{m}^{2}}\] is tied rigidly at both the ends.  The temperature of the wire is altered from \[40{}^\circ C\] to \[20{}^\circ C.\] Coefficient of linear expansion for steel \[\alpha =1.1\times {{10}^{-5}}/{}^\circ C\] and Y for steel is \[2.0\times {{10}^{11}}N/{{m}^{2}}.\] The change in tension of the wire is

A) \[2.2\times {{10}^{6}}\]newton

B)        16 newton

C) 8 newton          

D)        44 newton