Question

The work function of aluminum is 4.2 eV. If two photons each of energy 3.5 eV strike an electron of aluminum, then emission of electron will be

• A. depends on the density of the surface
• B. not possible
• C. possible
• D. none of these

Answer 1

The correct option is B not possible

Emission of photo electrons from the metal surface takes place only when the energy of the incident photon is greater than the work function of the metal surface.
Since here, energy of incident photon is less than work function of metal surface. So emission of electron is not possible.