KCET2022PhysicsDual Nature of Matter
The kinetic energy of the photoelectrons increases by 0.52 eV when the wavelength of incident light is changed from 500 ~nm to another wavelength which is approximately
Options
- A400 ~nm
- B1250 ~nm
- C1000 ~nm
- D700 ~nm
Correct answer
A. 400 ~nm
Step-by-step solution
Given, change in kinetic energy of photoelectrons, aligned K & =0.52 eV ₁ & =500 ~nm , ₂=? aligned We know that, kinetic energy of emitted photoelectron (using Einstein's equation) gathered K= h c - At wavelength ₁ K₁= h c ₁ - gathered At wavelength _ 2^ K₂= h c ₂ - From Eqs. (i) and (ii), we have array cc & K₂-K₁= h c ₂ - h c ₁ K=h c ( 1 ₂ - 1 ₁ ) 0.52=1242 ( 1 ₂ - 1 500 ) array array rlrl & & 0.52 1242 & = 1 ₂ - 1 500 & 1 ₂ & = 0.52 1242 + 1 500 & & ₂ & 400 ~nm array