In an $X$-ray tube,electrons bombarding the target produce $X$-rays of minimum wavelength $1\; \mathring{A}$. What must be the energy of the bombarding electrons in $eV$?

$A$ metal target with atomic number $Z=46$ is bombarded with a high-energy electron beam. The emission of $X$-rays from the target is analyzed. The ratio $r$ of the wavelengths of the $K_\alpha$-line and the cut-off wavelength is found to be $r=2$. If the same electron beam bombards another metal target with $Z=41$,the value of $r$ will be

When are characteristic $X$-ray emissions produced?

An electron beam strikes a target at an accelerating potential of $50 \,kV$. Which of the following frequencies of $X$-rays will not be obtained?

Which of the following is related to the characteristic emission of $X$-rays?

What determines the hardness of the $X-$rays obtained from the Coolidge tube?