If you have lamp with 300 W power output And the average wavelength of the source is 590nm how many photons are emitted per second?

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Answer 1 · 2018-06-04T22:49:17

$8.9 × 10^20$ photons

Let the number of photons emitted in one second be $"n"$ .

$"Power" = "Energy"/"Time"$

$"P" = ("nhc"/λ)/"t" = "nhc"/"λt"$

Rearrange the above equation

$"n" = "Ptλ"/"hc"$

$color(white)("n") = ("300 Watt × 1 s" × 590 × 10^-9\ "m")/(6.626 × 10^-34\ "J s" × 3 × 10^8\ "m/s")$

$color(white)("n") = 8.9 × 10^20$