Question

Explain the inverse linear dependence of stopping potential on the incident wavelength in a photoelectric effect experiment?

Answer 1

Stopping potential is directly proportional to (1/λ), which means it increases when wavelength of incident light is decreases.

• According to the photoelectric effect, when a light beam of specific wavelength strikes on the metal surface, electrons are ejected and kinetic energy of each electron is discharged - K.E_max = hc/λ - Φ
• Potential stoppage is the minimum amount of negative potential that photoelectric current becomes zero for. it is given by - K.E_max = eV_0, where V_0 is the stopping potential.
• Thus, eV_0 = hc/λ - Φ = V_0 = (hc/e)1/λ- Φ/e