JEE Advanced 2014 Paper 1

During Searle’s experiment, zero of the Vernier scale lies between 3.20×10−2m and 3.25×10−2m of the main scale. The 20th 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 3.20×10−2m and 3.25×10−2m 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 8×10−7m2.The least count of the Vernier scale is 1.0×10−5m The maximum percentage error in the Young’s modulus of the wire is