Need to understand this problem .thanks\

Problem 1. A photoelectric experiment was carried out with a Sodium cathode with a clean surface. The work function this cathode is 2.75eV. The wavelength of the incident light on cathode surface is 216nm. The experiment result is shown in the photoelectric current vs. anode voltage Figure below. Please draw a new curve for the new result onto the existing curve in Figures above, (a) if the cathode material is changed from Sodium to Cesium with a work function of 2.14eV, while maintaining the same incident light, (b) if the incident light on cathode surface is changed to a wavelength of 292nm while keeping the Sodium as the cathode material