Question

A band brake consists of a lever attached to one end of the band. The other end of the band is fixed to the ground. The wheel has a radius of $200mm$ and the wrap angle of the band is ${270}^{\circ }$. The braking force applied to the lever is limited to $100N$, and the coefficient of friction between the band and the wheel is $0.5$. No other information is given.
The maximum wheel torque that can be completely braked is

• A. $200N.m$
• B. $382N.m$
• C. $604N.m$
• D. $844N.m$

Answer 1

The correct option is B $382N.m$

Braking torque
$=(T_1-T_2)\times r$
$=(2110-200)\times 0.2=382Nm$