A 2,mW laser operates at a wavelength of 500, | vedclass

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(D) The power $P$ of the laser is given by $P = n \cdot E_{photon},$ where $n$ is the number of photons emitted per second and $E_{photon} = \frac{hc}

Vedclass · Accepted Answer

$5 	imes 10^{15}$

Vedclass · Answer

(D) The power $P$ of the laser is given by $P = n \cdot E_{photon},$ where $n$ is the number of photons emitted per second and $E_{photon} = \frac{hc}{\lambda}.$Given $P = 2\,mW = 2 	imes 10^{-3}\,W,$ $\lambda = 500\,nm = 500 	imes 10^{-9}\,m,$ $h = 6.6 	imes 10^{-34}\,Js,$ and $c = 3.0 	imes 10^8\,m/s.$Rearranging for $n$: $n = \frac{P \cdot \lambda}{h \cdot c}$Substituting the values:$n = \frac{2 	imes 10^{-3} 	imes 500 	imes 10^{-9}}{6.6 	imes 10^{-34} 	imes 3.0 	imes 10^8}$$n = \frac{1000 	imes 10^{-12}}{19.8 	imes 10^{-26}}$$n = \frac{10^{-9}}{19.8 	imes 10^{-26}} \approx 0.0505 	imes 10^{17} = 5.05 	imes 10^{15} \approx 5 	imes 10^{15}.$Thus,the number of photons emitted per second is $5 	imes 10^{15}.$

$A$ $2\,mW$ laser operates at a wavelength of $500\,nm.$ The number of photons that will be emitted per second is [Given Planck's constant $h = 6.6 \times 10^{-34}\,Js,$ speed of light $c = 3.0 \times 10^8\,m/s$]

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