The velocity of photons is proportional to (where $\nu=$ frequency)

The wavelength of a photon with energy $35 \text{ keV}$ is . . . . . . .
$(h = 6.625 \times 10^{-34} \text{ J s}, c = 3 \times 10^{8} \text{ m/s}, 1 \text{ eV} = 1.6 \times 10^{-19} \text{ J})$

An ultraviolet bulb emits light of wavelength $400 \ nm$ and an infrared bulb emits light of wavelength $700 \ nm$. If both are rated at $130 \ W$,what is the ratio of the number of photons emitted per second by the $UV$ and $IR$ sources?

When an $X$-ray photon collides with a proton,its frequency:

If the energy of a photon is $10\,eV$,then its momentum is

The number of photons emitted by a $10\,W$ bulb in $10\,s,$ if the wavelength of light is $1000\,\mathring{A},$ is: