Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800Å. Calculate threshold frequency (V_(0)) and work function (W_(0)) of metal.

Electrons are emitted with zero velocity from a metal surface when it

1.	Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800Å. Calculate threshold frequency (V_(0)) and work function (W_(0)) of metal.
Answer» Solution :`"Given "= 6800Å = 6800 xx 10^(-8) cm` `= 6.8 xx10^(-5) cm` `therefore v_(0)=(c)/(lambda)=(3xx10^(10)" cm. SEC"^(-1))/(6.8xx10^(-5)cm)=0.44xx10^(15)s^(-1)` `=4.4xx10^(14)s^(-1)" (or HZ)"` `W_(0)=h lambda_(0)=6.625xx10^(-27)" erg. Sec" xx4.4xx10^(14)S^(-1)`. `29.15xx10^(-13)" erg. For 1 PHOTO ELECTRON."`