Shear stress is _____ stress.
Try it first: pick an option, then read the explanation.
Correct answer: D. tangential
Asked in SSC JE 23/09/2019 (Evening)
Detailed Explanation
Stress on a plane can be split into two components: one perpendicular to the plane (normal stress — tension or compression) and one lying in the plane (shear stress).
Why “tangential” Is Correct
Because the shear component acts along the surface, it is called a tangential stress. It distorts the shape of the element (angle change) rather than changing its length.
| Stress | Direction relative to the plane | Effect |
|---|---|---|
| Normal (tensile/compressive) | Perpendicular | Change in length/volume |
| Shear (tangential) | Parallel | Change in shape (shear strain γ) |
Why the Other Options Are Wrong
- A. bending: Bending stress is a normal stress that varies linearly over the depth.
- B. normal: Normal stress acts perpendicular to the plane — the opposite of shear.
- C. proof: Proof stress is a strength value (0.2 % offset), not a type of stress.
Key Point
Normal stress ⟂ plane; shear (tangential) stress ∥ plane.
Key Concepts for Students
- τ = Gγ in the elastic range.
- Complementary shear stresses on perpendicular planes are equal.
- Rivets, bolts and keys are designed mainly for shear.
Practice more: this is question 12 in Bending and Shear Stress MCQs – Part 1. Try the whole set and check every answer instantly.