1. The problem statement, all variables and given/known data It is a homework question and I solved it in the following way: To Prove that (∆θ)(∆L)~(ћ/2) ;For what uncertainty of L will the angular position of the particle would be indeterminate? 2. Relevant equations 3. The attempt at a solution I considered a particle of mass m moving in a circle of constant radius r at speed v.Then,classically,L=mvr. Clearly,from uncertainty principle, ∆s ∆p~(ћ/2) => (∆s/r)[(∆p)r]~(ћ/2) => (∆θ)(∆L)~(ћ/2) What I am worried if this particular case of a circle will do;and the second question.I think it is ∆L=0 which makes ∆θ indeterminate...But I am not sure... Please check if this is correct and rectify if I am wrong.