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GATE 2020 ME (ME1) – Question 17

Mechanics of Materials · Transformation of stress and strain, Mohr circle · 1 mark · Multiple choice

The stress state at a point under plane stress is equibiaxial tension of magnitude 10 MPa. If one unit on the σ–τ plane represents 1 MPa, its Mohr representation is ______.

  1. a circle with radius equal to the principal stress and centre at the origin of the σ–τ plane
  2. a point on the σ axis at a distance of 10 units from the origin
  3. a circle with radius of 10 units on the σ–τ plane
  4. a point on the τ axis at a distance of 10 units from the origin

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Correct answer: (B) a point on the σ axis at a distance of 10 units from the origin

Explanation

The circle centre is (σx+σy)/2=10 MPa. Its radius is √[((σx−σy)/2)²+τxy²]=0. Hence the in-plane circle degenerates to **(10,0), B**. The out-of-plane principal stress zero is irrelevant to the requested in-plane representation.