The idea of the quantum nature of light has emerged in an attempt to explain:

Estimating the following two numbers should be interesting. The first number will tell you why radio engineers do not need to worry much about photons! The second number tells you why our eye can never 'count photons',even in barely detectable light.
$(a)$ The number of photons emitted per second by a Medium wave transmitter of $10\; kW$ power,emitting radiowaves of wavelength $500\; m$.
$(b)$ The number of photons entering the pupil of our eye per second corresponding to the minimum intensity of white light that we humans can perceive $(10^{-10}\; W m^{-2})$. Take the area of the pupil to be about $0.4\; cm^2$,and the average frequency of white light to be about $6 \times 10^{14}\; Hz$.

$A$ photon of $1.7 \times 10^{-13} \ J$ is absorbed by a material under special circumstances. The correct statement is:

Two sources of light emit with a power of $200 \ W$. The ratio of the number of photons of visible light emitted per second by each source having wavelengths $300 \ nm$ and $500 \ nm$ respectively,will be:

The average number of photons emitted per second by a laser of power $6.6 \times 10^{-3} \,W$ producing light of wavelength $600 \,nm$ is (Planck's constant,$h = 6.6 \times 10^{-34} \,J \cdot s$):

Which one of these is non-divisible?