Photoelectric Effect and the conversion ofPlank's constant from V.S to J.S

In summary, the conversation discusses how to calculate the value of Plank's constant using a graph of cut-off voltage versus frequency. The speaker mentions finding a slope of 4.224x10^-15 in V.s and asks for help converting it to J.s. They also mention the equation eV=change in kinetic energy and how to compare their calculated value to the accepted value of Plank's constant. The conversation ends with a question about the units of the gradient on a graph with eV or Joules on the y-axis and s^-1 on the x-axis.
  • #1
Hmpca
10
0
i graphed cut-off voltage verses frequency.
when i figured out plank's constant so when i calculated the slope of the function i got 4.224x10-15. My question is how to convert V.s to J.s for the value of hhereS the question

FINDING A VALUE OF PLANK'S CONSTANT FORM YOUR GRAPH.
calculate the slope of the graph (in V.s)
plank's constant is the slope of a graph of maximum kinetic evergy vs frequency so we need to convert cut-off coltage to maximum kinetic energy. we can use the equation.
eV=change in kinetic energy
because cut-off voltage just stops the most energetic electron.
convert the value of your slope to J.s and compare your value to the accepted value of plank's constant.
 
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  • #2
If you have plotted KEmax against frequency the units on each axis should be eV (or maybe Joules) and s^-1 (frequency unit)
Can you see what units the gradient of a graph on these axes will be?
 

Related to Photoelectric Effect and the conversion ofPlank's constant from V.S to J.S

1. What is the photoelectric effect?

The photoelectric effect is a phenomenon in which the emission of electrons from a material is triggered by the absorption of electromagnetic radiation, such as light.

2. How does the photoelectric effect relate to the conversion of Planck's constant from V.S to J.S?

Planck's constant is a fundamental constant in quantum mechanics that describes the relationship between the energy of a photon and its frequency. In the photoelectric effect, this constant is used to calculate the amount of energy required to eject an electron from a material, and thus can be used to convert between units of volts and joules.

3. Why is Planck's constant important in the study of the photoelectric effect?

Planck's constant plays a crucial role in understanding the photoelectric effect because it helps to explain the relationship between the energy of photons and the energy required to eject electrons from a material. Without this constant, it would be difficult to accurately predict and measure the behavior of electrons in the photoelectric effect.

4. How is Planck's constant determined experimentally?

Planck's constant is typically determined experimentally using the photoelectric effect itself. By measuring the current of photoelectrons ejected from a material at different frequencies of light, the value of Planck's constant can be calculated using the equation E = hf, where E is energy, h is Planck's constant, and f is the frequency of the incident light.

5. Can Planck's constant be calculated using other methods?

Yes, Planck's constant can also be determined experimentally through other methods, such as measuring the wavelengths of atomic spectra or analyzing the behavior of particles in particle accelerators. Additionally, it can also be calculated theoretically using other fundamental constants and equations in quantum mechanics.

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