Question

A parallel beam of monochromatic radiation of cross-section area A( < p a ²), intensity I and is incident on a solid conductingnfrequency 0fsphere of work function and radius 'a' The sphere is grounded by a conducting wire Assume that for each incident photon one photoelectron is ejected Just after this radiation is incident on initially uncharged sphere, the current through the conducting wire is:

1.    
2.    
3.    
4. none of these