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A student determined Young's Modulus of elasticity using the formula Y= MgL^3 4 bd^3δ . The value of g is taken to be 9.8ms^-2 without any…

JEE Main 2021 — Physics Mechanics

2021mcqmedium

A student determined Young's Modulus of elasticity using the formula Y=MgL34bd3δ.Y=\frac{Mg{L}^{3}}{4{\mathrm{bd}}^{3}\delta }.Y=4bd3δMgL3​. The value of ggg is taken to be 9.8ms−29.8m{s}^{-2}9.8ms−2 without any significant error, his observations are as following.

Physical QuantityLeast count of the Equipment used for measurementObserved Value
Mass (M)(M)(M)1g1g1g2kg2\mathrm{kg}2kg
Length of bar (L)(L)(L)1mm1\mathrm{mm}1mm1m1m1m
Breadth of bar (b)(b)(b)0.1mm0.1\mathrm{mm}0.1mm4cm4\mathrm{cm}4cm
Thickness of bar (d)(d)(d)0.01mm0.01\mathrm{mm}0.01mm0.4cm0.4\mathrm{cm}0.4cm
Depression (δ)(\delta )(δ)0.01mm0.01\mathrm{mm}0.01mm5mm5\mathrm{mm}5mm
Then the fractional error in the measurement of YYY is :
Official previous-year question

Held on 1 Sept 2021 · Verified 6 Jul 2026.

Options

  1. A

    0.1550.1550.155

  2. B

    0.00830.00830.0083

  3. C

    0.0830.0830.083

  4. D

    0.01550.01550.0155

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