Penetrating power of $X-$rays depends on

Stopping potentials of $24, 100, 110$ and $115 \ kV$ are measured for photoelectrons emitted from a certain element (with $24 \ kV$ minimum) when it is irradiated with monochromatic $X-rays$. If this element is used as a target in an $X-ray$ tube,what will be the wavelength of the $K_{\alpha}$ line?

If the energy of an electron in the $K$-shell is $40000 \,eV$ and an accelerating potential of $60000 \,eV$ is applied across a Coolidge tube,which of the following $X$-rays will be obtained?

$X$-rays and $\gamma$-rays of the same energies may be distinguished by

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

If the cathode-anode potential difference in an $X$-ray tube is $10^5 V$,then the maximum energy of an $X$-ray photon can be: