The figure shows a plot of photocurrent versus anode potential for a photosensitive surface for three different radiations. Which one of the following is a correct statement?

Curves a and b represent incident radiations of different frequencies and different intensities Curves a and b represent incident radiations of same frequency but of different intensities Curves b and c represent incident radiations of different frequencies and different intensities Curves b and c represent incident radiations of same frequency having same intensity

Curves a and b represent incident radiations of same frequency but of different intensities

The energy of the incident photon is $h\nu$. Hence frequency determines the energy of incident photons. This energy is imparted on the photosensitive surface to cause photo ejection. At the points where curve cuts the x axis, the incident photon energy is equal to the work potential of material. Hence energy, hence frequency, is same for radiation of curves a & b.   Intensity is the measure of number of photons striking per unit time. Thus they determine the amount of photocurrent produced. Thus it is same for b & c.