# What if I double the frequency of incident light in photoelectric effect?

The photoelectric effect occurs when the frequency of incident radiation is above a threshold frequency. If we double this incident frequency, what effect will it have on the experiment? Also what will happen if we double the wavelength?

• Please take the time to use proper grammar and capitalization in your questions. I fixed this one for you, but in the future please do it yourself. It is a courtesy to the people take time to answer your questions – DanielSank Jul 8 '15 at 21:53

$h\nu =\frac{hc}{\lambda}=\frac{1}{2}mv^2+W_0$, where $W_0$, the energy needed to reap the electron from the atom, is constant per type of atom. Thus $v=\sqrt{\frac{2(h\nu-W_0)}{m}}=\sqrt{\frac{2(\frac{hc}{\lambda}-W_0)}{m}}$
As long as $h\nu=\frac{hc}{\lambda}>W_0$ - the electrons will be reaped from the metal. Changing frequency/wavelength of the photons won't change the number of reaped electrons, but will change their speed/kinetic energy.
• It's embedded in the $h\nu=\frac{hc}{\lambda}>W_0$ condition – Alexander Jul 8 '15 at 23:37