Question

Silver has a work function of 4.7 eV. When ultraviolet light of wavelength 100 nm is incident on it, a potential of 7.7 V is required to stop the photoelectrons from reaching the collector plate. How much potential will be required to stop photoelectrons when light of wavelength 200 nm is incident on it?

• A. 154 V
• B. 235 V
• C. 385 V
• D. 1.5 V

Hint:

The stopping potential decreases as the wavelength of the incident light increases because the energy of the photons decreases.

Answer 1

The Correct Option is D

Using the photoelectric equation \( E_k = h \nu - \phi \), where \( E_k \) is the kinetic energy, \( h \) is Planck's constant, \( \nu \) is the frequency of light, and \( \phi \) is the work function, we can calculate the stopping potential for different wavelengths. For light with a longer wavelength, the stopping potential decreases.