PHOTOELECTRIC EFFECT
Photoelectric effect was discovered by Heinrich Hertz in 1887. Photoelectric effect is a phenomenon in which electrons are emitted from the surface of a substance when certain electromagnetic radiation falls on it. Metal surfaces require ultra-violet radiation while caesium oxide needs a visible light i.e. optical spectrum (sunlight). Work function A minimum amount of work is needed to remove an electron from its energy level so as to overcome the forces binding it to the surface. This work is known as the work function with units of electron volts (eV). One electron volt is the work done when one electron is transferred between points with a potential difference of one volt; that is, 1 eV = 1 electron × 1 volt 1 eV = 1.6 × 10-19 × 1 volt 1 eV = 1.6× 10-19 Joules (J) Threshold frequency This is the minimum frequency of the radiation that… Read More »PHOTOELECTRIC EFFECT