MHT CET202311 May 2023Morning ShiftPhysicsDual Nature of MatterActual
The maximum kinetic energies of photoelectrons emitted are K₁ and K₂ when lights of wavelengths ₁ and ₂ are incident on a metallic surface. If ₁=3 ₂ then
Options
- AK ₁= K ₂ 3
- BK ₁ < K ₂ 3
- CK ₁=3 ~K ₂
- D3 ~K ₁=2 ~K ₂
Correct answer
B. K ₁ < K ₂ 3
Step-by-step solution
Kinetic energy of the photoelectrons K = hc - For wavelength ₁ , K ₁= hc ₁ - For wavelength ₁ , K ₂= hc ₂ - Subtracting equation (i) from equation (ii), aligned & K ₂- K ₁= hc ₂ - - hc ₁ + & K ₂- K ₁= hc ₂ - hc 3 ₂ & ~K ₂- K ₁= 2 3 hc ₂ & hc ₂ = 3 2 ( ~K ₂- K ₁ ) aligned Substituting equation (iii) in equation (ii), aligned & K ₂= 3 2 ( ~K ₂- K ₁ )- & 2 ~K ₂=3 ~K ₂-3 ~K ₁-2 & K ₂-3 ~K ₁=2 & As , >0 & ~K ₂-3 ~K ₁>0 & ~K ₁ < K ₂ 3 aligned