Question

An electron is accelerated from rest through a potential difference of V volt. If the de Broglie wavelength of the electron is $1.227 \times 10^{-2}nm$, the potential difference is :

• A. $10$ V
• B. $10^2$ V
• C. $10^3$ V
• D. $10^4$ V

Answer 1

Answer: (D)

$10^4$ V

Answer 2

$\lambda = 1.227 \times 10^{-2}\,m$
$=0.1227 \, ?$
$\lambda=\frac{12.27}{\sqrt{V}} ?$
$0.1227 = \frac{12.27}{\sqrt{V}} ?$
$\sqrt{V}\times10^{2}$
$\Rightarrow V=10^{4}$