 #1
Aurora_b
 4
 3
 Homework Statement:
 Why KE_(max) depends on frequency but doesn't depend on intensity? (This isn't exactly my homework but a related conceptual doubt i have in order to solve the homework questions)
 Relevant Equations:

So the confusion arose when my teacher wrote the equation for photoelectric effect:
KE_max = hf  W  eqn 1)
where,
KE_max = maximum kinetic energy of ejected electrons.
f= frequency of incident radiation
W= work function of the metal
Then the teacher wrote the formula for intensity
I = Nhf/A  eqn 2)
where,
N = no of photons incident per unit time
f= frequency of incident radiation
A= Area
Then the following statement was made:
Statement 1: KE_max depends on frequency but doesn't depend on Intensity.
I would believe the last statement if Intensity only depended on N but it also depends on the frequency f. Now if Intensity depends on f we can also find a relationship between KE_max and Intensity by substituting from eqn 2) in eqn 1)
KE_max = IA/N  W
So if KE_max depends on f and I depends on f then we can find the dependence between KE_max and I.
I understand I am wrong and that statement 1 is correct but I am just unable to convince myself, because everyowhere the reasoning is that I depends on N so it is independent but I also depends on f. Please help me understand.
KE_max = IA/N  W
So if KE_max depends on f and I depends on f then we can find the dependence between KE_max and I.
I understand I am wrong and that statement 1 is correct but I am just unable to convince myself, because everyowhere the reasoning is that I depends on N so it is independent but I also depends on f. Please help me understand.