Let n r and n b be respectively the number of photons emitted by a red bulb and a blue bulb of equal power in a given time.

Question

Philoid · Accepted Answer

The number of photons crossing an area in a given time is given by

=Intensity of source or power density; =Energy of a single photon; =Planck constant; =Velocity of photon; =Wavelength of light and =Frequency of light.

We know the famous mnemonic VIBGYOR (Violet-Indigo-Blue-Green-Yellow-Orange-Red) to remember visible light in increasing order of their wavelengths. We observe that red light has greater wavelength than blue light i.e. . From the above equation, we see that and therefore.

Let nr and nb be respectively the number of photons emitted by a red bulb and a blue bulb of equal power in a given time.

Let n_r and n_b be respectively the number of photons emitted by a red bulb and a blue bulb of equal power in a given time.