An e-m wave of wavelength `lambda` is incident on a photo sensitive surface of negligible work function. If the photoelectrons emitted from this surface have the de-Broglie wavelength `lambda_(1)`. Find relation between `'lambda'` and `'lambda_(1)`'-

Options

A. `lambda = ((2mc)/(h))lambda_(1)^(2)`
B. `lambda = ((mc)/(2h))lambda_(1)^(2)`
C. `lambda_(1) = ((2mc)/(h))lambda^(2)`
D. None of these

Answer

A

Explanation

`(1)/(2)mv^(2) = hv`
or `(p^(2))/(2m) = (hc)/(v)`
`lambda_(1) = (h)/(p) = (h)/(sqrt(((2mhc))/(lambda)))=sqrt((hlambda)/(2mc))`
or `lambda_(1)^(2) = (hlambda)/(2mc)`
`lambda = ((2mc)/(h))lambda_(1)^(2)`