question_answer

A tapering bar (diameters of end sections being \[{{d}_{1}}\] and\[{{d}_{2}}\]) and a bar of uniform cross-section 'd' have the same length and are subjected to the same axial pull. Both the bars will have the same extension if  'd' is equal to

A) \[\frac{{{d}_{2}}+{{d}_{2}}}{2}\]                  

B) \[\sqrt{{{d}_{1}}{{d}_{2}}}\]

C) \[\sqrt{\frac{{{d}_{1}}{{d}_{2}}}{2}}\]                       

D) \[\sqrt{\frac{{{d}_{2}}+{{d}_{2}}}{2}}\]