1.

Ultraviolet light of wavelength 280 nm is used in an experiment on photoelectric effect with lithium ( varphi = 2.5 eV) cathode. Find (a) the maximum kinetic energy of the photoelectrons and (b) the stopping potential.

Answer»

Solution : (a) The maximum kinetic energy is
` K_max = (hc/lambda)- varphi. `
`= (1242 eV nm/ 280 nm)- 2.5 eV. `
` = 4.4 eV - 2.5 eV = 1.9eV. `
(B) STOPPING potential V is given by
` eV= K_max`
` or, V=(K_max)/E = 1.9 eV/e = 1.9 V.`


Discussion

No Comment Found

Related InterviewSolutions