Work function of a metal is the maximum amount of energy required by an
Channel: Doubtnut
Date: 02/08/2020

Work function of a metal is the maximum amount of energy required by an electron, to just escape form the metal surface without any kinetic energy. The expression for work function of metal is `phi_(0)=hv_(0)=hc//lambda_(0)`, where h is Planck's constant, `v_(0)` is the threshold frequency, `lambda_(0)` is the threshold wavelength and c is the velocity of light in vacuume. Read the above paragraph and answer the following questions:  (i) Why different metals have different work function?  (ii) What is the threshold wavelength of the incident radiation for a metal surface whose work function is `1.2 eV. Given h=6.63xx10^(-34)Js, 1eV=1.6xx10^(-19)J`.  (iii) What do you learn from this study?