Respuesta :
Answer:
a) No. of photons/s = 246961 x [tex]10^{24}[/tex]
b) No. of photons/s = 72.43 x [tex]10^{17}[/tex]
c) No. of photons/s = 28.125 x [tex]10^{13}[/tex]
Explanation:
Given total power of electromagnetic radiation = 180 W = 180 j/s
a)Given source of frequency γ = 1100kHz
=1100 x [tex]10^{3}[/tex] Hz
We know that, Energy of each photon E = hγ
where h = 6.626 x [tex]10^{-34}[/tex] Js is planck's constant
E = 6.626 x [tex]10^{-34}[/tex] x 1100 x [tex]10^{3}[/tex]
= 7288.6 x [tex]10^{-31}[/tex]J
Total energy of all photons = 180 j/s
No. of photons = [tex]\frac{Total energy of all photons}{Energy of each photon}[/tex]
= [tex]\frac{180 J/s}{7288.6x10^{-31} }[/tex]
= 246961 x [tex]10^{24}[/tex]
b) Given wavelength λ = 8nm
We know that c= γλ
where c=3x[tex]10^{8}[/tex] m[tex]s^{-1}[/tex] is velocity of light
Therefore, frequency γ = c/λ
= [tex]\frac{3 x 10^{8} }{8x10^{-9} }[/tex]
= 0.375 x [tex]10^{17}[/tex]
Also we know that E = hγ
= 6.626 x [tex]10^{-34}[/tex] x 0.375 x [tex]10^{17}[/tex]
= 2.485 x [tex]10^{-17}[/tex]
Hence no. of photons = [tex]\frac{180}{2.484x10^{-17} }[/tex]
= 72.43 x [tex]10^{17}[/tex]
c) Given Energy of each photon = 4 MeV
We know that 1 Mev = 1.6 x [tex]10^{-13}[/tex] J
Therefore Energy of each photon = 4 x 1.6 x [tex]10^{-13}[/tex] J
= 6.4 x [tex]10^{-13}[/tex] J
No. of photons = [tex]\frac{180}{6.4x10^{-13} }[/tex]
= 28.125 x [tex]10^{13}[/tex]
