$X$-rays are used for the structural analysis of crystals because:

In a Coolidge tube experiment, the minimum wavelength of the continuous $X-$ray spectrum is equal to $66.3\, pm$. Then:

If the energy of a $K$-shell electron is $-40000 \ eV$ and a potential of $60000 \ V$ is applied to a Coolidge tube,which of the following $X$-rays will be formed?

$\Delta \lambda$ is the difference between the wavelength of the $K_\alpha$ line and the minimum wavelength of the continuous $X$-ray spectrum when the $X$-ray tube is operated at a voltage $V$. If the operating voltage is changed to $V / 3$,then the above difference is $\Delta \lambda^{\prime}$. Then:

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

The $X$-rays produced by a Coolidge tube consist of . . . . .