The maximum distance between the inter-atomic planes of a crystal is $10^{-7} \ cm$. The maximum wavelength of $X$-rays that can be studied by this crystal is ........... $\mathring{A}$.

The wavelength of the most energetic $X$-rays emitted when a metal target is bombarded by $40 \ keV$ electrons is approximately ....... $\mathring{A}$. $(h = 6.62 \times 10^{-34} \ J \cdot s; 1 \ eV = 1.6 \times 10^{-19} \ J; c = 3 \times 10^8 \ m/s)$

The potential difference applied to an $X-$ray tube is increased. As a result,in the emitted radiation:

Moseley's law relates the frequencies of line $X$-rays with the following characteristics of the target element:

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?

The minimum wavelength of $X$-rays produced by an electron accelerated through a potential difference of $V$ volts is proportional to: