Concepts Of Physics MCQ Edition [Volume 2]PhysicsPhotoelectric Effect and Wave–Particle Duality
A photographic film is coated with a layer of silver bromide. When light strikes this film, the silver bromide molecules dissociate, and the film records the light. A minimum of 0.6 eV is required to dissociate a silver bromide molecule. Determine the maximum wavelength of light that can be recorded by the film.
Options
- A4140 nm
- B2070 nm
- C3105 nm
- D1035 nm
Correct answer
B. 2070 nm
Step-by-step solution
The minimum energy required to dissociate a silver bromide molecule is given as E = 0.6 eV . The energy of a photon is related to its wavelength by the equation E = hc . For maximum wavelength, the energy of the photon must be equal to the minimum dissociation energy. _ max = hc E_ min Substituting hc = 1242 eV nm and E_ min = 0.6 eV : _ max = 1242 0.6 nm _ max = 2070 nm