$X$-rays which can penetrate through longer distances in substances are called

The $X$-ray wavelength of the $L_{\alpha}$ line of platinum $(Z=78)$ is $1.30 \ \mathring{A}$. The $X$-ray wavelength of the $L_{\alpha}$ line of Molybdenum $(Z=42)$ is ............. $\mathring{A}$.

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:

The wavelength of the $K_\alpha$ $X$-ray line for a given element is $0.32 \, \mathring{A}$. The wavelength of the $K_\beta$ line emitted by the same element will be ... $\mathring{A}$.

$X$-rays are used for the structural analysis of crystals because:

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: