Which of the following wavelengths falls in the $X-$ray region in $\mathring{A}$?

The maximum wavelength of hard $X$-rays required for the study of bone fractures is $10^{-11} \ m$. The accelerating voltage in the $X$-ray machine must be:

Electrons of mass $m$ with de-Broglie wavelength $\lambda$ fall on the target in an $X$-ray tube. The cutoff wavelength $(\lambda_0)$ of the emitted $X$-ray is

Penetrating power of $X-$rays depends on

For the study of bone fractures,the minimum wavelength of $X$-rays should be $10^{-11} \ m$. The accelerating voltage for electrons in the $X$-ray machine will be .......

The structure of solids is investigated by using