An $X$-ray tube has a short wavelength limit at $0.45 \mathring{A}$. The voltage of the tube is ........ $V$.

$X$-rays,when incident on a metal,do which of the following?

In tungsten,the energy of a $K$-shell electron is $20 \, keV$ and that of an $L$-shell electron is $2 \, keV$. When an electron jumps from the $L$ shell to the $K$ shell,the wavelength of the emitted $X$-ray photon will be:

Frequency of the $K_{\alpha}$ $X$-ray for the element calcium $(Ca, Z = 20)$ is $8.95 \times 10^{17} \ Hz$. The frequency of the $K_{\alpha}$ $X$-ray for the element cadmium $(Cd, Z = 48)$ will be:

Characteristic $X$-rays are produced due to

If the operating voltage of an $X$-ray tube is $50 \, kV$,then the velocity of the $X$-rays is . . . . .