The minimum wavelength of $X$-rays produced in a Coolidge tube operated at a potential difference of $40 \ kV$ is ....... $\mathring{A}$.

The power input in an $X$-ray tube is increased by:

The intensity of $X$-rays from a Coolidge tube is plotted against wavelength as shown in the figure. The minimum wavelength found is ${\lambda _c}$ and the wavelength of the ${K_\alpha }$ line is ${\lambda _k}$. As the accelerating voltage is increased:

When $0.50\; \mathring{A}$ $X$-rays strike a material,the photoelectrons from the $K$-shell are observed to move in a circle of radius $23\; mm$ in a magnetic field of $2 \times 10^{-2}\; T$ acting perpendicularly to the direction of emission of photoelectrons. The binding energy of $K$-shell electrons is $..........\; keV$.

Which one of the following statements is $WRONG$ in the context of $X$-rays generated from an $X$-ray tube?

Characteristic $X$-rays are produced due to