10.A brass rod of cross-sectional area

10. A brass rod of cross-sectional area 1cm²  and length 0.2 m is compressed lengthwise by a weight of 5 kg. If Young’s modulus of elasticity of brass is 1×10¹¹ N/m²  and g=10 m/sec² , then increase in the energy of the rod will be

(a)  10^-5   J                                                 (b) 2.5×10^-5  J

(c)  5×10^-5 J                                              (d)  2.5×10^-4 J

Answer-b