Physics Circle home Student Login

Home›Chapters›Units, Dimensions and Measurement PYQs›Errors in Measurement›Question 70

JEE Main 2023 (8 Apr, Shift 1) · Errors in Measurement

Errors in Measurement question from JEE Main 2023 (8 Apr, Shift 1)

Q70JEE Main 2023 · 8 APR · SHIFT 1Easy

Errors in Measurement

A cylindrical wire of mass (0.4±0.01) g(0.4 \pm 0.01)\text{ g} has length (8±0.04) cm(8 \pm 0.04)\text{ cm} and radius (6±0.03) mm(6 \pm 0.03)\text{ mm}. The maximum error in its density will be:

Show answer and solution

Answer: (c)

  1. ρ=mπr2l\rho = \frac{m}{\pi r^2 l}, so Δρρ=Δmm+2Δrr+Δll\frac{\Delta\rho}{\rho} = \frac{\Delta m}{m} + 2\frac{\Delta r}{r} + \frac{\Delta l}{l}
  2. =0.010.4+2⋅0.036+0.048=2.5%+1%+0.5%= \frac{0.01}{0.4} + 2\cdot\frac{0.03}{6} + \frac{0.04}{8} = 2.5\% + 1\% + 0.5\%
  3. So the answer is (c) 4%.
Report a mistake

More questions on Errors in Measurement