Photoelectrons are emitted when 400 nm radiation is incident on a surface of
Channel: Doubtnut
Date: 2020-07-05

Photoelectrons are emitted when 400 nm radiation is incident on a surface of work - function 1.9 eV. These photoelectrons pass through a region containing a-particles. A maximum energy  electron combines with an a -particle to  from a `He^+` ion, emitting a single photon in this process. `He^+` ions thus formed are in their fourth excited state. Find the energies in eV of the photons lying in the  2 to 4 eV range, that are likely to be emitted during and after the combination. `[Take, h = 4.14xx10^(-15) eV -s]`