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A rod of length l has non-uniform linear mass density given by ρ (x)=a+b( x )^2, where a and b are constants and 0≤ x≤ l The value of x for the…

JEE Main 2020 — Physics Mechanics

2020mcqmedium

A rod of length lll has non-uniform linear mass density given by ρ(x)=a+b(xl)2,\rho (x)=a+b{(\frac{x}{l})}^{2},ρ(x)=a+b(lx​)2, where aaa and bbb are constants and 0≤x≤l0\leq x\leq l0≤x≤l The value of xxx for the centre of mass of the rod is at:

Official previous-year question

Held on 9 Jan 2020 · Verified 6 Jul 2026.

Options

  1. A

    32(a+b2a+b)L\frac{3}{2}(\frac{a+b}{2a+b})L23​(2a+ba+b​)L

  2. B

    34(2a+b3a+b)L\frac{3}{4}(\frac{2a+b}{3a+b})L43​(3a+b2a+b​)L

  3. C

    43(a+b2a+3b)L\frac{4}{3}(\frac{a+b}{2a+3b})L34​(2a+3ba+b​)L

  4. D

    32(2a+b3a+b)L\frac{3}{2}(\frac{2a+b}{3a+b})L23​(3a+b2a+b​)L

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