If the potential difference $V$ applied to the Coolidge tube is doubled, then the cut-off wavelength

Characteristic $X$-rays are not obtained in the spectrum of a hydrogen atom because,

In an $X$-ray tube,when the accelerating voltage is increased from $10 \ kV$ to $20 \ kV$,the difference between the wavelength of the $K_\alpha$ line and the short-wavelength limit of the continuous spectrum increases by a factor of $3$. The atomic number of the target element is:

For the production of $X$-rays, the target should be made of

If $X$-rays are produced by bombarding electrons with an energy of $40 \ keV$ on a target,what will be the minimum wavelength (in $\mathring{A}$) of the $X$-rays produced?

Calculate the wavelength of the $K_{\alpha}$ line for $Z=31$, when $a=5 \times 10^7 \, Hz^{1/2}$ for a characteristic $X$-ray spectrum.