Experimental arrangement to determine Young`s modulus of a figure material wire under tension as shown in the figure. Two identical wires of same length and radius suspended side by side from a fixed rigid support. Reference wire A carries millimetre main scale M and a pan to place the weight. Experimental wire B also carries a pan in which known weights can be placed. Vernier scale V is attached to a pointer at the bottom of the experimental wire helps to find elongation of wire. Both wire are given an initial small load to keep straight and initial reading is noted. Now experimental wire is gradually loaded with more weights and reading is noted. The difference between two reading gives elongation ∆L of the wire of initial length L and radius r for a load mass M. The Young`s modulus of the material of the experimental wire is given by
