Question

__________ is the wavelength of photon of energy $35$KeV.
$h=6.625\times {10}^{-34}$J-s, $c=3\times {10}^8$m/s, $1$eV$=1.6\times {10}^{-19}$J.

• A. $35\times {10}^{-12}$m
• B. $35\stackrel{o}{A}$
• C. $3.5$nm
• D. $3.5\stackrel{o}{A}$

Answer 1

The correct option is A $35\times {10}^{-12}$m

Energy of photon $E=35KeV$
$\therefore$ $E=35\times 1000\times 1.6\times {10}^{-19}J=5.6\times {10}^{-15}J$
Wavelength of photon $\lambda =\frac{hc}{E}$
$⟹\lambda =\frac{6.625\times {10}^{-34}\times 3\times {10}^8}{5.6\times {10}^{-15}}=35\times {10}^{-12}m$