A light of energy 5eV falls on a metal and the electrons with a maximum kinetic energy of 2eV are ejected. The work function of the metal is

Answer Details

When light of energy 5eV falls on a metal, it can cause electrons to be ejected from the surface of the metal. The maximum kinetic energy of these electrons is 2eV. The work function of a metal is the minimum amount of energy needed to remove an electron from the surface of the metal. We can use the formula: Maximum kinetic energy of electrons = Energy of the incident light - Work function Rearranging the formula to solve for the work function: Work function = Energy of the incident light - Maximum kinetic energy of electrons Plugging in the given values: Work function = 5eV - 2eV = 3eV Therefore, the work function of the metal is 3.0eV. Option (c) is the correct answer.