On a disc of radius `R` a concentric circle of radius `R//2` is drawn. The disc is free to rotate about a frictionless fixed axis through its center and perpendicular to plane of the disc. All three forces `(` in plane of the disc `)` shown in figure are exerted tangent to their respective circular periphery. The magnitude of the net torque `(` about centre of disc `)` acting on the disc is `:`

Options

A. `1.5 FR`
B. `1.9 FR`
C. `2.3 FR`
D. `2.5 FR`

Answer

A

Explanation

Toreque `tau = (2f)R + F((R)/(2)) + FR(-1) = (3FR)/(2)`