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Physics · LAWS OF MOTION
हिन्दीGiven below are four statements regarding frictional forces and contact interactions: (A) Static friction is a self-adjusting force whose magnitude is strictly equal to \( \mu_s N \) at all times. (B) The kinetic friction force is virtually independent of the microscopic area of contact for a given pair of solid surfaces. (C) The angle of friction is equal to the angle of repose for an object on an inclined plane on the verge of sliding. (D) The magnitude of limiting static friction is directly proportional to the normal reaction force. Which of the above statements are correct?
Correct answer · Option 3
(B), (C) and (D) only
Explanation
Statement (A) is false because static friction adjusts between \( 0 \) and \( \mu_s N \); it is equal to \( \mu_s N \) ONLY at maximum/limiting value. Statements (B), (C), and (D) are correct standard laws of friction.
