h ( V – Vo ) = ½ meV 2
Experimental results observed for the experiment of Photoelectric effect-
o When beam of light falls on a metal surface electrons are ejected immediately .
o Number of electrons ejected is proportional to intensity or brightness of light
o Threshold frequency ( vo ): For each metal there is a characteristic minimum frequency below which photoelectric effect is not observed . This is called threshold frequency .
o If frequency of light is less than the threshold frequency there is no ejection of electrons no matter how long it falls on surface or how high is its intensity .
Photoelectric work function ( Wo ): The minimum energy required to eject electrons is called photoelectric work function . Wo = hvo
h ( V – Vo ) = ½ meV 2
Energy of the ejected electrons :
Dual behavior of electromagnetic radiation- The light possesses both particle and wave like properties , i . e ., light has dual behavior . whenever radiation interacts with matter , it displays particle like properties .( Black body radiation and photoelectric effect ) Wave like properties are exhibited when it propagates ( interference an diffraction )
When a white light is passed through a prism , it splits into a series of coloured bands known as spectrum .
Spectrum is of two types : continuous and line spectrum
a . The spectrum which consists of all the wavelengths is called continuous spectrum .