A 100W sodium lamp radiates energyuniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength of the sodium light is 589 nm. (a) what is the energy per photon associated with the sodium light? (b) At what rate are the photons delivered to the sphere ?

A 100W sodium lamp radiates energyuniformly in all directions. The lam

1.	A 100W sodium lamp radiates energyuniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength of the sodium light is 589 nm. (a) what is the energy per photon associated with the sodium light? (b) At what rate are the photons delivered to the sphere ?
Answer» Solution :Here `LAMDA=589nm=5.89xx10^(-7)m` and power of LAMP `P=100W` (a) Enerrgy per photon of SODIUM light `E=(hc)/(lamda)=(6.63xx10^(-34)xx3xx10^(8))/(5.89xx10^(-7))J=3.38xx10^(-19)J=2.11eV` (b) Number of photons delivered per second `n=(P)/(E)=(100W)/(3.38xx10^(-19)J)=2.95xx10^(20)s^(-1)=3xx10^(20)s^(-1)`.

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