Question

the no. of photons of light of wavelength 7000Å equivalent to 1J are ?

Answer 1

hey here is your answer

E=hc/wavelength

=6.626×10^-34Js×3×10^8/7000×10^-10m

=2.8397×10^-19J

so no of photon=1/2.8398×10^-19

=3.5214×10^18

Answer 2

Answer:

Energy, E=  

λ

hc

​  

 

Energy of a single  photon of wavelength 7000 Angstrom is  

7000×10  

−10

 

hc

​  

   

put h=6.6×10  

−34

Joule−second and c=3×10  

8

m/s  

we get energy of a single photon as E=2.829×10  

−19

Joule

Number of photon in 1 Joule=  

E

1J

​  

=3.52×10  

18

 

Explanation: