Question

The stopping potential (\[{\upsilon _0}\])
A. Depends upon the angle of incident light
B. Depends upon the intensity of incident light
C. Depends upon the surface nature of the substance
D. Is independent of the intensity of the incident light

Answer 1

Hint: Stopping potential is defined as the minimum negative voltage applied to the anode to stop the photocurrent. Maximum kinetic energy of the electrons equals the stopping voltage, when measured in electron volt. Here we find the stopping potential depends on what factors.

Formula used:
The energy of the photon is given by the equation is given as:
\[E = h\upsilon = \dfrac{{hc}}{\lambda }\\
\Rightarrow e{V_0} = h\upsilon \]
Where, \[h\] is the Plank constant, \[\upsilon \] is the frequency, c is the speed of light
\[\lambda \] is the wavelength, e is the charge of electrons and \[{V_0}\] is the stopping potential.
Kinetic energy of photoelectrons is given by:
\[KE = E - \phi \]
Where E is the energy of the photon and \[\phi \] is the work function.

Complete step by step solution:
As we know the energy of the photon is,
\[E = h\upsilon \\
\Rightarrow e{V_0} = h\upsilon = \dfrac{hc}{\lambda }\]
From the above relation we can conclude that stopping potential is dependent on the frequency and wavelength. Thus stopping potential does not depend on intensity of incident radiation. Therefore, we can say that it is dependent on the frequency as well as the wavelength and is independent of the intensity of the incident light.

Hence option D is the correct answer

Note: Stopping potential is the potential required to stop photoelectric effect. Stopping potential is defined as the potential required for stopping the ejecting of an electron from a metal surface when the incident light energy is greater than the work potential of the metal. On the intensity of incident radiation, stopping potential does not depend. On increasing intensity, the value of saturated current increases, whereas the stopping potential remains unchanged.