Question

Calculate the energy of photon of light having frequency ${3\times 10}^5$Hz. If wavelength of light is $\lambda \left(0.50AA\right)$ , then calculate its energy.

Answer 1

If frequency $=3\times {10}^{5}Hz$

$E=hv$

$=6.626\times {10}^{-34}J/s-1\times 3\times {10}^5=19.878\times {10}^{-29}J$

if $\lambda =0.5\times {10}^{-10}$

we know $c=\lambda v$

$v=3\times {10}^8/0.5\times {10}^{-10}=6\times {10}^{18}$

$E=hv$

$=6.626\times {10}^{-34}J/s-1\times 6\times {10}^{18}=3.97\times {10}^{-15}J$