Question

Nitrogen laser produces a radiation at a wavelength of 337.1 nm. If the number of photons emitted is 5.6 × ${10}^{24}$, calculate the power of this laser.

Answer 1

Power of laser = Energy with which it emits photons
Power= $=E=\frac{Nhc}{\lambda }$
Where,
N = number of photons emitted
h = Planck’s constant
c = velocity of radiation
λ = wavelength of radiation
Substituting the values in the given expression of Energy (E):
E= $\frac{(5.6\times {10}^{24})(6.626\times {10}^{-34}Js)(3\times {10}^{8}m{s}^{-1})}{(337.1\times {10}^{-9}m)}=0.3302\times {10}^{7}J=3.33\times {10}^{6}J$
Hence, the power of the laser is $3.33\times {10}^{6}J/s$

$Hence3.3\times {10}^{6}Watt$