Photelectric Effect Intensity question

[Elnino_Gerrard]

Tsfx 2009. When it gives a graph of photocurrent  versus voltage. The grap drawn is of orange light of intensity 5.0 w/m^2
Now it says, draw a graph if violet light was used.
1) Stopping voltage would be greater
2) The photocurrent is also lower??? (can someone please explain why this is the case?)

[ssluffy]

since violet light has a greater energy, given by a higher frequency, it would require less photons to produce a 5.0 Wm^-2 light.

Watts = N*Energy/Time
Watts/Metres^2 = (N*Energy)/(Time*Metres^2)

where N is the number of photons.
Since Energy is higher (with the violet light), the N value decreases to give the same amount of intensity.
Since incident photons are now lower in number, the photocurrent also decreases.

[Elnino_Gerrard]

ahh i see  ..Thanks mate