Light of a single frequency falls on a photoelectric material, but no electrons are emitted.On the contrary, if the electrons are to be emitted, then which of the following options willcause it?

Explanation

The photoelectric effect occurs when photons with energy equal to or greater than the material's work function strike the surface and release electrons. Increasing the frequency of the incident light will increase the energy of the photons, potentially allowing them to overcome the work function and emit electrons. Decreasing the frequency or increasing the intensity does not increase the energy per photon and hence does not help in electron emission. Using a material with a higher work function would require even higher frequency light for electron emission.