Question

Calculate the wavelength of a photon having an energy of $2$ electron volt.

• A. $6.204\times {10}^{-7}m$
• B. $6.206\times {10}^{-6}m$
• C. $6.204\times {10}^{-9}m$
• D. $6.204\times {10}^{-8}m$

Answer 1

Answer: (A)

$6.204\times {10}^{-7}m$

According to the formula,

$\begin{array}{c}E=\frac{hc}{\lambda }\\ \lambda =\frac{hc}{E}=\frac{6.626\times {10}^{-34}\times 3\times {10}^8}{2\times 1.6\times {10}^{-19}}\\ =6.204\times {10}^{-7}m\end{array}$