22. A wire of length L and cross-sectional area A is made of a material of Young’s modulus Y. It is stretched by an amount x. The work done is

(a) (YxA)/(2L)                                                        (b) (Yx² A)/(L)

(c)  (Yx² A)/(2L)                                                    (d)  (2Yx² A)/(L)

Answer-c