$X-$rays are in nature similar to

In vacuum,an electron of energy $10 \ keV$ hits a tungsten target. The emitted radiation will be:

The frequencies of $K_{\alpha}$,$K_{\beta}$,and $L_{\alpha}$ $X$-rays of a material are $\nu_1$,$\nu_2$,and $\nu_3$ respectively. Which of the following relations holds good?

$X$-rays are not used for radar purposes because:

The wavelength of the series limit of the Lyman series in the hydrogen spectrum is $911 \ \mathring{A}$. Calculate the atomic number of the element that emits characteristic $X$-rays with a minimum wavelength of $0.7 \ \mathring{A}$.

The energy of a photon of characteristic $X-$ rays from a Coolidge tube comes from