1. In photoelectric experiment, if anode potential w.r.t. cathode is increased, photocurrent first increases then becomes a constant, since all the photoelctorns ejected from cathode are collected at anode. If we increase the intensity of light at this point, the 'saturation current' increases because number of photons incident per unit time increases. Now the problem is, if we increase the frequncy now keeping the intensity constant, that would mean we are decreasing number of photons incident per unit time, which should result in reduction of current. Number of photons per unit time = IA/hf . It is clear that number of photons strking per unit time will decrease, and current must drcrease. However every textbook of physics that i have states that saturation photocurrent will not change when frequncy is changed but intensity is kept constant. http://dronstudy.com/wp-content/uploads/2014/02/124.jpg In this graph, frequencies are different but intensity is same. By my logic, saturation current should be different. But is shown to be same for all frequencies. Any ideas/ solutions are welcome. Thankyou for your time.