Question

The Davisson-Germer experiment that first demonstrated the wave nature of matter used electrons accelerated to 54 V. Determine the wavelength $\left(\text{in}{A}^{\circ }\right)$ of the electrons in the Davisson-Germer experiment. (Answer upto 2 decimal places)

Answer 1

Method - I
$\lambda =\frac{h}{p}=\frac{h}{\sqrt{2mK}}=\frac{h}{\sqrt{2me{V}_s}}\lambda =\frac{6.63\times {10}^{-34}}{\sqrt{2\times 9.1\times {10}^{-31}\times 1.6\times {10}^{-19}\times 54}}$
$\lambda =1.67A^{\circ }$
Method - II
$\lambda =\frac{12.27}{\sqrt{v}}{A}^{\circ }$
$\lambda =\frac{12.27}{\sqrt{54}}$
$=1.67A^{\circ }$