Principle and Working:
Einstein postulated that light consists of a quantum of particles, called photon whose energy E is proportioned to the frequency n, by an equation, E = hn, where h is planck’s constant.In this experiment, narrow band interference filters are used to select wave length. Each filter selects precisely one spectral line from the light of a high pressure mercury lamp. The monochromatic light falls on the cathode of the photocell. A capacitor, connected between cathode and anode of photocell, charged by anode, is used. Electrometer amplifier is used to measure the voltage at capacitor without current.
