The angle between the direction of the maximum principal plane and the maximum shear plane is
- A30°
- B45°Correct
- C60°
- Dnone of the above
Solution
Concept
Orientation of principal and shear planes
Step-by-step solution
1. Principal planes: τ = 0. 2. Planes of maximum shear are at 45° to them (90° on the Mohr circle).
Explanation
On the Mohr circle the principal stresses are at the ends of a horizontal diameter and the maximum shear at the top, 90° apart on the circle, so 45° in the body.
Why the other options are wrong
30° and 60° are not special orientations here.
Shortcut
Max shear plane = 45° from principal plane.
Common mistake
Choosing 90°.
Correct answer: B) 45°