Hold at rest

Classical Mechanics Level 3

Find the maximum wavelength of light in nano-meters that can cause photoelectric effect in silver? Enter the integer part of your answer.

Details And Assumptions:

1 solution

Rachit Shukla
Nov 21, 2015

$K_\max = h\,f - \varphi$

For maximum wavelength, K.E. should be minimum. $(K.E.=0)$

$\Rightarrow$ $h\,f = \varphi$

$\Rightarrow$ $\frac {hc}{\lambda}=\varphi$

$\Rightarrow$ $\frac {4.14\times10^{-15}\times3\times10^8}{\lambda}=4.7$

$\Rightarrow$ $\lambda\approx2.642\times10^{-7}m$

$\therefore \lambda\approx264.2 nm$

$\boxed{Ans: 264}$