The forces $F_1$ and $F_2$ in a brake band and the direction of rotation of the drum are as shown in the figure. The coefficient of friction is 0.25. The angle of wrap is $\frac{3\pi}2$ radians. It is given that R = 1 m and $F_2$ = 1 N. The torque (in N-m) exerted on the drum is _________