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 $$200$$ $$mm$$ 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

In a band brake the ratio of tight side band tension to the tension on the slack side is $$3.$$ If the angle of overlap of band on the drum is $${180^ \circ }$$ the coefficient of friction required between drum and the band is