JEE Advanced 2014 Paper 1 Physics Q12

Physics · Solids & Fluids · Foundations & Measurement

Problem

During Searle's experiment, zero of the Vernier scale lies between

3.20\times10^{-2}\,\mathrm{m}

and

3.25\times10^{-2}\,\mathrm{m}

of the main scale. The

20^{\mathrm{th}}

division of the Vernier scale exactly coincides with one of the main scale divisions. When an additional load of

2\,\mathrm{kg}

is applied to the wire, the zero of the Vernier scale still lies between

3.20\times10^{-2}\,\mathrm{m}

and

3.25\times10^{-2}\,\mathrm{m}

of the main scale but now the

45^{\mathrm{th}}

division of Vernier scale coincides with one of the main scale divisions. The length of the thin metallic wire is

2\,\mathrm{m}

and its cross-sectional area is

8\times10^{-7}\,\mathrm{m^2}

. The least count of the Vernier scale is

1.0\times10^{-5}\,\mathrm{m}

. The maximum percentage error in the Young's modulus of the wire is