During Searle's experiment, zero of the Vernier scale lies between $3.20 imes 10^{-2} \mathrm{~m}$

Question

During Searle's experiment, zero of the Vernier scale lies between $3.20 	imes 10^{-2} \mathrm{~m}$ and $3.25 	imes 10^{-2} \mathrm{~m}$ of the main scale. The $20^{	ext {th }}$ division of the Vernier scale exactly coincides with one of the main scale divisions. When an additional load of 2 kg is applied to the wire, the zero of the Vernier scale still lies between $3.20 	imes 10^{-2} \mathrm{~m}$ and $3.25 	imes 10^{-2} \mathrm{~m}$ of the main scale but now the 45th division of Vernier scale coincides with one of the main scale divisions. The length of the thin metallic wire is 2 m and its cross-sectional area is $8 	imes 10^{-7} \mathrm{~m}^{2}$. The least count of the Vernier scale is $1.0 	imes 10^{-5} \mathrm{~m}$. The maximum percentage error in the Young's modulus of the wire is ________ .

Professor PC Thomas Classes · Answer

(4)\