The values of theta that represent the angle b/w orbital quantum no. (l) & magnetic field direction can never by pi or 0 deg as then the magnetic quantum no . will have non integral values & and also the direction of orbital quantum no . & magnetic field will be parallel which means the electron will have circular orbit which is not possible as a particle under the action of a central force field has elliptical orbit . No cone around the magnetic field will be traced out . Is my reasoning correct ??