Mohr’s Circle MCQ – Objective Questions with Answers
Mechanical Engineering › Strength of Materials | Free practice MCQs with detailed explanations
Last Updated: June 2026
📌 About this MCQ Set
Mohr’s circle is a graphical method for finding principal stresses, maximum shear stress and stresses on any plane from a known state of plane stress.
These MCQs cover the construction of the circle, principal stresses and the angle relationship.
8 questions • every answer comes with a worked explanation. Click Show Answer to check yourself.
📖 New to this topic? Read the full concept guide: Mohr’s Circle →
Mohr’s Circle MCQs
Q1. Mohr’s circle is a graphical method to determine:
Show Answer
Answer: B. Stresses on inclined planes / principal stresses
Mohr’s circle gives normal and shear stresses on any plane, the principal stresses and the maximum shear stress.
Q2. The centre of Mohr’s circle lies at:
Show Answer
Answer: B. ((σx+σy)/2, 0)
The centre is at ((σx + σy)/2, 0) on the normal-stress axis.
Q3. The radius of Mohr’s circle equals:
Show Answer
Answer: B. √(((σx−σy)/2)² + τxy²)
Radius R = √(((σx − σy)/2)² + τxy²), which is also the maximum shear stress.
Q4. On the principal planes, the shear stress is:
Show Answer
Answer: B. Zero
Principal planes are defined as the planes on which shear stress is zero.
Q5. The principal stresses are given by:
Show Answer
Answer: A. Centre ± radius
σ1,2 = centre ± radius = (σx+σy)/2 ± R.
Q6. The maximum shear stress equals:
Show Answer
Answer: B. (σ1−σ2)/2
Maximum in-plane shear stress = (σ1 − σ2)/2 = radius of Mohr’s circle.
Q7. An angle of 2θ on Mohr’s circle corresponds to a physical plane rotation of:
Show Answer
Answer: B. θ
Angles on Mohr’s circle are double the physical angles: 2θ on the circle = θ on the element.
Q8. On the principal planes, the normal stresses are:
Show Answer
Answer: B. Maximum and minimum
Principal stresses are the maximum and minimum normal stresses, occurring where shear is zero.
Frequently Asked Questions
What is Mohr’s circle used for?
It is a graphical tool to find principal stresses, maximum shear stress and the stresses acting on any inclined plane for a given state of plane stress.
Why are angles doubled on Mohr’s circle?
Because the stress-transformation equations contain 2θ terms; therefore a rotation of θ on the physical element corresponds to 2θ on the circle.
What do the points where the circle crosses the normal-stress axis represent?
The principal stresses, where the shear stress is zero.