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

The potential difference between the cathode and the target in a Coolidge tube is $100 \ kV$. The minimum wavelength of the $X$-rays emitted by the tube is

The wavelengths of $K_\alpha$ lines of two elements are $250 \, pm$ and $179 \, pm$, respectively. The number of elements between these two elements in the periodic table will be:

An electron beam in an $X$-ray tube is accelerated through a potential difference of $50000 \ V$. These are then made to fall on a tungsten target. The shortest wavelength of the $X$-ray emitted by the tube is

The characteristic $X$-rays depend on .........

Why is a direct $X$-ray photograph of the intestines not taken by a radiologist?