Question

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

Ans plzz

Answer 1

Given,

The inverse linear dependence of stopping potential on the incident wavelength in a photoelectric effect experiment.

To explain,

relation between stopping potential and incident wavelength in a photoelectric effect.

according to photoelectric effect,

when a beam of light of specific wavelength (or frequency) strikes on the surface of metal, sum amount of electrons eject from it and kinetic energy of each electron is given by,

K.E_max = hc/λ - Φ

stopping potential is the minimum amount of negative (or retarding ) potential for which photoelectric current becomes zero. it is given by, K.E_max = eV_0

where V_0 is stopping potential.

so, eV_0 = hc/λ - Φ

⇒V_0 = (hc/e)1/λ- Φ/e

here it is clear that stopping potential is directly proportional to (1/λ). means stopping potential increases when wavelength of incident light is decreases. see graph of stopping potential and incident wavelength.