AP EAMCET2002PhysicsDual Nature of Matter
Two photons of energies twice and thrice the work function of a metal are incident on the metal surface. Then, the ratio of maximum velocities of the photoelectrons emitted in the two cases respectively, is
Options
- A2 : 1
- B3 : 3
- C3 : 2
- D1: 2
Correct answer
D. 1: 2
Step-by-step solution
Let the work function of the metal be W Then energy of Ist photon E₁=2 W Energy of IInd photon E₂=3 ~W Maximum KE of photoelectron ( KE )_ =E-W (Einstein's equation) For first photon ( KE ₁ )_ =2 W-W=W For second photon ( KE ₂ )_ =3 W-W aligned & =2 W ( K E ₁ )_ ( K E ₂ )_ & = 1 2 aligned array r 1 2 m v₁^2 1 2 m v₁^2 = 1 2 v₁ v₂ = 1 2 v₁: v₂=1: 2 array