Allied & ICAR Exam Bank • ALLIED_2818MSQ • 2 Marks
Section 2: Farm Machinery
Machine Design
Subtopic: Measurement of force, stress, torque, speed, displacement and acceleration on machine elements – shafts, couplings, keys, bearings and knuckle joints
Question Statement:
Which of the following failure modes must be checked in the design of a square or rectangular key?
Options:
(A) Shear failure along the horizontal pitch plane of the key
(B) Crushing (bearing) failure against the keyway side face
(C) Torsional fatigue along key length
(D) Euler column buckling
Answer Key:
A, B
Step-by-Step Solution & Explanation
Keys are standardly evaluated against two critical failure modes: shear stress $\tau = \frac{F}{w L}$ and compressive bearing stress $\sigma_c = \frac{F}{(h/2) L}$.