MHT CET202410 May 2024Evening ShiftPhysicsDual Nature of MatterActual
When a photosensitive surface is irradiated by lights of wavelengths ' ₁ ' and ' ₂ ', kinetic energies of the emitted photoelectrons is ' E₁ ' and ' E₂ ' respectively. The work function of the photosensitive surface is
Options
- A(E₂ ₂-E₁ ₁ ) ( ₂- ₁ )
- B(E₁ ₁+E₂ ₂ ) ( ₂- ₁ )
- C(E₁ ₁-E₂ ₂ ) ( ₂- ₁ )
- D(E₂ ₂+E₁ ₁ ) ( ₁- ₂ )
Correct answer
C. (E₁ ₁-E₂ ₂ ) ( ₂- ₁ )
Step-by-step solution
From Einstein's photoelectric equation, aligned & E ₁= hc ₁ - W ₀ & E ₁ ₁= hc - W ₀ ₁ & E ₂= hc ₂ - W ₀ & hc = E ₁ ₁+ W ₀ ₁...(i) aligned array ll & E ₂ ₂= hc - W ₀ ₂ & hc = E ₂ ₂+ W ₀ ₂...(ii) array From equations (i) and (ii), array ll & E ₁ ₁+ W ₀ ₁= E ₂ ₂+ W ₀ ₂ & E ₁ ₁- E ₂ ₂= W ₀ ( ₂- ₁ ) & W ₀= E ₁ ₁- E ₂ ₂ ₂- ₁ array