could someone plz help me with the following
A particular filament rating of 60W emits 5% of this power as visible light. The average wavelength of visible light is 550nm.
Calculate the number of photons of visible light emitted per second from the lamp.
Thanks
The 5% power is defined as the energy required for
number of photons to be emitted per second.
Hence Power =
x
where
= photon energy =
/lambda
Power =
x
/lambda -----> 5/100 x 60 =
x (6.63 x 10
-34) x (3 x 10
8) / (550 x 10
-9)
Thus
is found to be
8.3 x 1018 which is the required answer.
Sorry for late reply...........but I was kinda busy.