Stopping Potential Question

• DarkMatter5
In summary, the potential difference that the electron is accelerated through must be 12431.25 volts in order to produce some X-Ray photons of wavelength 10-10 meters.

Homework Statement

Electrons are accelerated through a potential V and then they are suddenly stopped and emit photons. Derive the minimal value that the potential should have in order to produce some X-Ray photons of wavelength 10-10m.

E=hc/λ
V=(h/e)(f-f0)

The Attempt at a Solution

I used E=hc/λ to find the energy of the X ray photons. I found E= 1.989x10-15 = 12431.25 eV

Not sure if I needed to do this or what to do next. All help is appreciated. Thank you.

Hi DarkMatter5, Welcome to Physics Forums!

DarkMatter5 said:

Homework Statement

Electrons are accelerated through a potential V and then they are suddenly stopped and emit photons. Derive the minimal value that the potential should have in order to produce some X-Ray photons of wavelength 10-10m.

E=hc/λ
V=(h/e)(f-f0)

The Attempt at a Solution

I used E=hc/λ to find the energy of the X ray photons. I found E= 1.989x10-15 = 12431.25 eV

Not sure if I needed to do this or what to do next. All help is appreciated. Thank you.
You have found the energy, and cleverly expressed it in electron volts. What electric potential difference (Volts) should the electron be accelerated through in order to achieve that energy?

By the way, you might want to round your result to suit the given significant figures.

DarkMatter5
gneill said:
Hi DarkMatter5, Welcome to Physics Forums!You have found the energy, and cleverly expressed it in electron volts. What electric potential difference (Volts) should the electron be accelerated through in order to achieve that energy?

By the way, you might want to round your result to suit the given significant figures.

I guess it would be 12431.25 V? And is it to 1 sig fig? so 1 x 104 V?

Yup.

DarkMatter5
gneill said:
Yup.
Thank you very much!

What is the "Stopping Potential Question"?

The "Stopping Potential Question" is a concept in physics that refers to the minimum potential difference required to stop the emission of electrons from a metal surface.

How is the stopping potential measured?

The stopping potential is measured by applying a varying potential difference to a metal surface and observing the point at which the emission of electrons stops.

What factors affect the value of the stopping potential?

The value of the stopping potential is affected by the work function of the metal, the intensity of the incident light, and the frequency of the incident light.

What is the significance of the stopping potential in the photoelectric effect?

The stopping potential is significant in the photoelectric effect because it is directly proportional to the maximum kinetic energy of the emitted electrons. It also helps to determine the threshold frequency of the metal.

How is the stopping potential related to Einstein's photoelectric equation?

The stopping potential is related to Einstein's photoelectric equation as it is equal to the difference between the incident light's energy and the work function of the metal. This equation helps to explain the relationship between the frequency of the incident light and the energy of the emitted electrons.