Einstein's Photoelectric Equation and its graph

In summary: The slope of the line corresponds to the rate of increase of Ek with respect to f, and the y-intercept corresponds to the point at which Ek equals hf.
  • #1
Bloopy
13
1
According to the equation, the graph of kinetic energy of emitted photoelectrons from a metal vs the frequency of incident radiation gives a straight line.

My doubt is, what factors does the slope of this line depend on? I think it depends on the nature of metal used. Correct me if I am wrong.
 
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  • #2
Hi Bloopy, :welcome:
Bloopy said:
According to the equation,
It looks as if you know which equation that is. Can you write it up in a post ?
 
  • #3
I know this.
 

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  • #4
Bloopy said:
I know this.

This is really not an "equation". So let's start all over again. Can you write down the Einstein's photoelectric effect equation?

Zz.
 
  • #5
Bloopy said:
I know this.
And what do you think of the mathematical description in the Wikipedia lemma right beside this picture ?
 
  • #6
ZapperZ said:
Can you write down the Einstein's photoelectric effect equation?

Energy supplied=Work Function + Kinetic Energy
 
  • #7
Bloopy said:
Energy supplied=Work Function + Kinetic Energy

I am not quite sure why you are being a bit difficult, or if you don't quite know what you are doing.

So, if I write this:

Ek = hf - φ

where Ek is the maximum kinetic energy of the photoelectrons, h is the Planck constant, f is the frequency of light, and φ is the work function, do you understand that this is the photoelectric effect equation, similar to what you wrote, or do you need an explanation for this?

Zz.
 
  • #8
ZapperZ said:
or do you need an explanation for this?
I am on the same page as you
 
  • #9
Bloopy said:
No, I am on the same page

Not sure what page you're on, but OK.

Now, I will make the assumption that you know the mathematics for the equation of a straight line, i.e.

y = mx + b

so, I will not explain the meaning of that equation (this is the math that you should already know by the time you tackle this physics).

The graph you referred to in your original post is a graph of Ek versus f, i.e. Ek plotted in the vertical axis, and f in the horizontal axis. Make a visual identification of these two equations:

y = mx + b
Ek = hf - φ

If you identify

y→Ek

and

x→f

then what corresponds to the slope of the line? As a bonus, what corresponds to the y-intercept of the line?

Zz.
 
Last edited:
  • Like
Likes Bloopy

1. How did Einstein's Photoelectric Equation change the understanding of light?

Einstein's Photoelectric Equation demonstrated that light behaves as both a wave and a particle. This challenged the previously accepted theory that light only behaved as a wave.

2. What is the Photoelectric Effect and how does it relate to Einstein's Equation?

The Photoelectric Effect is the phenomenon where electrons are emitted from a metal surface when light of a certain frequency is shone on it. Einstein's Equation explains this effect by showing that light energy is absorbed by individual electrons, causing them to be emitted from the metal surface.

3. How is the Photoelectric Equation graph interpreted?

The Photoelectric Equation graph shows the relationship between the frequency of light and the kinetic energy of emitted electrons. The slope of the graph represents Planck's constant, while the y-intercept represents the work function of the metal surface.

4. Can the Photoelectric Equation be applied to all metals?

No, the Photoelectric Equation can only be applied to certain metals that have a low work function. Metals with higher work functions require a higher frequency of light to cause the emission of electrons.

5. What is the significance of the Photoelectric Equation in modern technology?

The Photoelectric Equation has led to the development of important technologies such as solar panels, photodiodes, and photomultiplier tubes. These technologies rely on the Photoelectric Effect to convert light energy into electrical energy.

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