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QJEEM21Phb777: JEE Main 2021 Physics - Class 11 JEEM21Phb777 Solution: A uniform heavy rod of weight 10 kg ms − 2 , cross-sectional…

A uniform heavy rod of weight 10 kg ms−2, cross-sectional area 100 cm2 and length 20 cm is hanging from a fixed support. Young modulus of the material of the rod is 2 × 1011 Nm−2. Neglecting the lateral contraction, find the elongation of rod due to its own weight.

Multiple Choice Options

  • A 2 × 10−9 m
  • B 5 × 10−8 m
  • C 4 × 10−8 m
  • D 5 × 10−10 m

Step-by-Step Verified Solution

JEE Main 2021 (Online) 31st August Morning Shift Physics - Properties of Matter Question 154 English Explanation
We know,

Δl=WL2AY

Δl=10×12×5×100×10−4×2×1011

Δl=12×10−9=5×10−10 m

Option (d)

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