What is the minimum size of a washing cup for netilat yadayim? If there is no washing cup available, is it sufficient to put one’s hands directly under a faucet?

Dear David: The minimum size for a washing cup is one that holds a revi'it (about 3.3 oz or 95 g). If you are washing your hands in the morning (as opposed to washing before bread), if no cup is available, most authorities permit washing directly under the faucet. In that case, I recommend you turn the faucet on and off in bursts, so that you are not washing your hands under a steady stream.