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Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीA rigid door is hinged along a vertical axis. A constant force \( F \) of given magnitude is to be applied to open the door. Which of the following conditions ensures that the torque produced about the hinge line is maximum?
Correct answer · Option 3
Force is applied at the outer edge, perpendicular to the plane of the door.
Explanation
Torque is \( \tau = r F \sin\theta \). To maximize torque, the lever arm \( r \) must be maximum (at the outer edge) and the angle \( \theta \) must be \( 90^\circ \) (perpendicular to the door).
