Hard $X$-rays for the study of fractures in bones should have a minimum wavelength of $10^{-11} \, m$. The accelerating voltage for electrons in the $X$-ray machine should be:

In the characteristic $X$-ray spectra of an atom superimposed on a continuous $X$-ray spectrum, identify the peaks $P$ and $Q$ shown in the graph.

When $X$-rays pass through a high-intensity uniform magnetic field,they:

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

$A$ metal target with atomic number $Z=46$ is bombarded with a high-energy electron beam. The emission of $X$-rays from the target is analyzed. The ratio $r$ of the wavelengths of the $K_\alpha$-line and the cut-off wavelength is found to be $r=2$. If the same electron beam bombards another metal target with $Z=41$,the value of $r$ will be

The energy of an $X$-ray photon of wavelength $1.65 \mathring{A}$ is ....... $keV$. $(h = 6.6 \times 10^{-34} \ J \cdot s, \ c = 3 \times 10^8 \ m/s, \ 1 \ eV = 1.6 \times 10^{-19} \ J)$ (in $.5$)