Question

Find the deBroglie wavelength of an electron with 4.0 eV.

Answer 1

Explanation:

It is given that,

Voltage, $V=4 eV=4\times 1.6\times 10^{-19}\ V= 6.4\times 10^{-19}\ V$

De broglie wavelength in terms of voltage is given by :

$\lambda=\dfrac{h}{\sqrt{2meV} }$

m and e are the mass and charge on electron. So,

$\lambda=\dfrac{12.27}{\sqrt{V} }\ A$

$\lambda=\dfrac{12.27}{\sqrt{6.4\times 10^{-19}} }\ A$  

$\lambda=1.53\times 10^{10}\ A$

$\lambda=1.53\ m$

So, the De broglie wavelength of an electron is 1.53 meters. Hence, this is the required solution.