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JEE Main202330 Jan 2023Evening ShiftPhysicsLaws of MotionActual

A block of 3 kg is attached to a string whose other end is attached to the wall. An unknown force F is applied so that the string makes an angle of 30 ° with the wall. The tension T is : (Given g = 10 m s – 2 )

Options

  1. A20   N
  2. B25   N
  3. C10   N
  4. D15   N

Correct answer

A. 20   N

Step-by-step solution

From geometry, θ = 30 ° . For equilibrium, T cos θ = m g ⇒ T = m g cos 30 ° ⇒ T = 3 × 10 3 2 ⇒ T = 20   N

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