Net force along verticle axis is zero and along redial provides centripertal acceleration

` mu N sin alpha + N cos alpha - mg = 0`
`N sin alpha - mu N cos alpha = m omega^(2) r`
`mg. ((sin alpha - mu N cos alpha))/((mu sin alpha + cos alpha))`
As block remain at same height and radial distance requirement of friction is same as in part (b)

Force of friction will remain unchanged Hence ratio as `L`