Answer:
[tex]n=2.68\times 10^{15}[/tex]photons/s
Yes,we can treat the light as a continuous electromagnetic wave in this case.
Explanation:
We are given that
Wavelength of photon=[tex]\lambda=532 nm=532\times 10^{-9}m[/tex]
1nm=[tex]10^{-9} m[/tex]
Power of photon=1mW=[tex]0.0010J/s[/tex]
We have to find the number of photons emit from laser.
In 1 s, photon emit energy=0.0010 J
We know that
[tex]E=nh\nu=nh\times \frac{c}{\lambda}[/tex]
Where c[tex]\c=3\times 10^8 m/s[/tex]
[tex]E=[/tex]Energy of photon
[tex]\lambda[/tex]=Wavelength of light
[tex]h=6.626\times 10^{-34}Js[/tex]
Substitute the values then, we get
[tex]0.0010=n\times 6.626\times 10^{-34}\times \frac{3\times 10^8}{532\times 10^{-9}}[/tex]
[tex]n=\frac{0.0010\times 532\times 10^{-9}}{6.626\times 10^{-34}\times 3\times 10^8}[/tex]
[tex]n=2.68\times 10^{15}[/tex]photons/s
Visible light is EM wave.
Range of wavelength of visible light =400nm- 700 nm
Green color lies in visible region because its wavelength lies in 400nm-700 nm.
Therefore, we can treat the light as a continuous electromagnetic wave in this case.
