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NEETPhysicsLaws of Motion

Assertion : A block of weight 10 N is pushed against a vertical wall by a force of 15 N. The coefficient of friction between the wall and the block is 0.6. Then, the magnitude of maximum frictional force is 9 N. Reason : For given system block will remain stationary.

Options

  1. AIf both Assertion and Reason are correct and Reason is the correct explanation of Assertion
  2. BIf both Assertion and Reason are true but Reason is not the correct explanation of Assertion
  3. CIf Assertion is true but Reason is false
  4. DIf Assertion is false but Reason is true

Correct answer

C. If Assertion is true but Reason is false

Step-by-step solution

- Normal reaction from the wall equals the horizontal push: ( N = 1 5 ~ N ), so maximum static friction f_max (= N =0.6 15=9 ~N ) (Assertion true). - To remain at rest, friction must balance weight 10 N , but available friction is only 9 N , so the block slides down; the "block will remain stationary" statement is false (Reason false).

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