Question

The number of photons emitted in ten hours by a 60w sodium lamp

Answer 1

Answer:

6.4×$10^{24}$

Explanation:

Energy of photon, E = hν = h(c/λ) = 3.374 x $10^{-19}$ J

[It is known that, h = 6.626 x $10^{-34}$ m² kg/s and c = 3 x 108 m/s]

Number of photons emitted by the sodium lamp in one second = [60 / 3.374 x $10^{-19}$]

∴ The number of photons emitted by the sodium lamp in 10 hours is

= [(60 x 10 x 3600)/ (3.374 x 10-19)] = 6.4 x $10^{24}$