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

$STATEMENT-1$: If the accelerating potential in an $X$-ray tube is increased, the wavelengths of the characteristic $X$-rays do not change. because
$STATEMENT-2$: When an electron beam strikes the target in an $X$-ray tube, part of the kinetic energy is converted into $X$-ray energy.

The binding energy of the innermost electron in tungsten is $40 \, keV$. The energy of the characteristic $X$-rays emitted is:

$X$-rays of wavelength $0.1 \ \mathring A$ are allowed to fall on a metal and get scattered. The wavelength of the scattered radiation is $0.111 \ \mathring A$. If $h = 6.624 \times 10^{-34} \ J \cdot s$ and $m_0 = 9 \times 10^{-31} \ kg$,then the direction of the scattered photons will be:

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

The minimum wavelength of $X$-rays produced in a Coolidge tube operating at $40 \ kV$ is ..... $\mathring A$.