If the energy of a photon with wavelength $6000 \ \mathring{A}$ is $3.32 \times 10^{-19} \ J$, then the energy of a photon with wavelength $4000 \ \mathring{A}$ is ............. $eV$.

$A$ bulb has a power of $60 \, mW$ and emits light of wavelength $6000 \, \mathring{A}$. Calculate the number of photons emitted by the bulb per second.

Given below are two statements:
Statement-$I$: Two photons having equal linear momenta have equal wavelengths.
Statement-$II$: If the wavelength of a photon is decreased,then the momentum and energy of the photon will also decrease.
In the light of the above statements,choose the correct answer from the options given below.

$A$ parallel beam of light of wavelength $900 \, nm$ and intensity $100 \, W/m^2$ is incident on a surface perpendicular to the beam. The number of photons crossing $1 \, cm^2$ area perpendicular to the beam in one second is:

Find the number of photons emitted per second by a $10 \ kW$ radio transmitter operating at a wavelength of $500 \ m$.

If $5\%$ of the energy supplied to a bulb is irradiated as visible light,how many quanta are emitted per second by a $100 \, W$ lamp? Assume the wavelength of visible light is $5.6 \times 10^{-5} \, cm$.