$A$ radio transmitter operates at a frequency of $880 \ kHz$ and a power of $10 \ kW$. The number of photons emitted per second is .......

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

The frequency of a photon having energy $100 \ eV$ is $(h = 6.6 \times 10^{-34} \ J \cdot s)$.

Calculate the number of photons entering the eye of a duck per second,corresponding to the minimum intensity of white light $(\sim 10^{-10} \ W/m^2)$. Take the area of the duck's eye as $0.4 \ cm^2$ and the average frequency of white light as $6 \times 10^{14} \ Hz$.

$A$ $60 \,W$ source emits monochromatic light of wavelength $662.5 \,nm$. The number of photons emitted per second is

Which scientist discarded the postulate of ether?