Is a beaker more precise in determining volume than an Erlenmayer flask???
Probably... More precise would be a graduated cylinder but if that's not an option I'd go with the beaker.
See my answer to a similar question below. It all depends upon the size of each and how much solvent is being estimated. Personally, I wouldn't use a beaker OR an Erlenmeyer flask for measuring a volume that I wanted to be very accurate. In general, however, you can estimiate volumes more accurately from a beaker because the sides of the Erlenmeyer flask are angular and the beaker is not (it is cylindrical).
Like Bob I wouldn't use either. However, if it comes down to a choice between the two with the same base area the conical is more precise. Lets say they are both are accurately marked at 250 ml and they both have a base diameter of 85 mm (just measured one) and the conical reduces to 34 mm diameter at the 250 ml line. If the error in reading the line is say 1 mm in each case, then I think you can see that there is a larger uncertainty in the volume in the beaker than in the conical flask even without doing the maths.
From a practical point of view I take the volumes marked on each as indicative as once they have been through through a wash, dry, oven cycle a few times who knows how accurate the markings are.
I agree with Dr Russ BUT see my earlier post to your same question four posts down the board. It all depends upon the size of the beaker, the size of the Erlenmeyer flask, the amount of solvent (H2O) and a myriad of other things. If the base is the same size AND the measurement is being made nearer the neck of the flask, then the flask is the more accurate. But I repeat that I woudln't use either.
Oh I agree. There is not a simple answer apart from using neither of them that is!