Question

A sphere kept on a rough inclined plane is in equilibrium by a string wrapped over it. If the angle of inclination is θ, the tension in the string will be equal to

• A. mg sin θ
• B.
• C. $\frac { m g \sin \theta } { 2 }$
• D. None of these

Answer 1

Answer: (C)

$\frac { m g \sin \theta } { 2 }$

Answer 2

Since f & N passes through the point P, their torque about P will be zero.

⇒ For the equilibrium of the sphere the torques of tension T & weight mg about P will be zero. ⇒ mg sin θ × r − T(2r) = 0

⇒ 2 Tr = mgr sin θ

⇒ T = ,