Question

A principal plane is a plane of

• A. minimum tensile stress
• B. maximum tensile stress
• C. zero shear stress
• D. maximum shear stress

Hint:

Principal planes are characterized by zero shear stress and the normal stress being maximum or minimum.

Answer 1

The Correct Option is C

Step 1: Define the principal planes.
In the theory of stress, principal planes are those planes where the shear stress is zero. These planes correspond to the principal stresses, which are the maximum and minimum normal stresses at a given point. Step 2: Conclusion.
Principal planes are the planes where the shear stress is zero and the normal stresses are at their extreme values. Final Answer: \[ \boxed{\text{zero shear stress}} \]