Free JEE Main Physics Friction MCQs with step-by-step solutions (1 questions). Part of Laws of Motion. Practise online on Prepizo — no login needed.
Q1 — Friction · medium · theory
A block rests on a rough inclined plane. As the angle of inclination increases, the block starts sliding when:
A. tan θ equals the coefficient of static friction ✓ Correct
B. sin θ equals the coefficient of static friction
C. cos θ equals the coefficient of static friction
D. θ becomes 90°
Solution: Sliding begins when the component of gravity along the incline (mg sin θ) exceeds maximum static friction (μ mg cos θ). At the verge of sliding, mg sin θ = μ mg cos θ, so tan θ = μ.