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GATE 2019 CE (CE2) – Question 15

Solid Mechanics · Uniform torsion and combined stresses · 1 mark · Multiple choice

A closed thin-walled tube has thickness t, mean enclosed area $A_m$ within its wall centreline, and shear stress τ. Find torsional resistance T.

  1. $0.5\tau A_mt$
  2. $\tau A_mt$
  3. $2\tau A_mt$
  4. $4\tau A_mt$

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Correct answer: (C) $2\tau A_mt$

Explanation

Bredt’s closed-cell relation is $T=2A_mq$, where shear flow $q=\tau t$. Therefore $T=2\tau A_mt$: **C**.