We know that intensity I = nhf, where n is no. of photons striking metal surface per second per unit sq unit area, and f is frequency of incident ray. In the book it was said that if we change the frequency of the incident keeping intensity constant, the saturation current doesn't vary.
But if intensity I is constant, then the quantity n should also change inversely with changing f, (since I= nhf). As a result, saturation current (which depends on n) should vary too. Why does this not happen?