When a certain photosensitive surface is illuminated with monochromatic light of frequency
u , the stopping potential for the photo current is - \frac{V_{0}}{2} . When the surface is illuminated by monochromatic light of frequency \frac{
u}{2} , the stopping potential is - V_{0} . The threshold f

When a certain photosensitive surface is illuminated with monochromatic light of frequency \nu , the stopping potential for the photo current is - \frac{V_{0}}{2} . When the surface is illuminated by monochromatic light of frequency \frac{\nu}{2} , the stopping potential is - V_{0} . The threshold f