What is cut-off frequency,wavelength related to photoelectric effect?
Previously light was considered as a wave. As we know, a wave is a form of energy. Energy travelling in particular direction. What would happen if we project a light beam on an atom. Well, the electron in an atom resides in a shell. That shell has a unique energy. If the electron is given energy or “excited”, it will jump to a higher shell, moving farther from nucleus. If we want to give energy through light, all we will need to do is to shine a light at the atom until its energy increased and it will jump up. At least that was what the scientists thought. Since it didn’t happen so, they had to deduce that light was not made up of wave but of particles called “Quantum” ( plural Quanta), Photons in case of light. These photons are small packets of energy that an electron eats and gets excited. So if you were to send an electron from a lower to higher shell with energy difference say 10 eV, you would need a light which have photon having energy equal to or greater than 10 eV. If we excit
