$X$-rays are produced due to

What is the speed of all types of electromagnetic radiation in a vacuum? What is it called?

The ejection of the photoelectron from the silver metal in the photoelectric effect experiment can be stopped by applying a stopping potential of $0.35 \ V$ when radiation of $256.7 \ nm$ is used. Calculate the work function for silver metal.

$A$ particular radio station broadcasts at a frequency of $1120 \, kHz$. Another radio station broadcasts at a frequency of $98.7 \, MHz$. What will be the wavelength of the radiation for each station?

Between a photon of violet light with a wavelength of $4000 \ \mathop A\limits^o$ and a photon of red light with a wavelength of $7000 \ \mathop A\limits^o$,which one has higher energy?

The wavelength of blue light is $480 \ nm$. What is the frequency of this light?