The variation of wavelength $\lambda$ of the $K_{\alpha}$ line with atomic number $Z$ of the target is shown by the following curve of

The diagram shows a graph between the intensity of $X$-rays emitted by a molybdenum target and the wavelength,when electrons of $30 \ keV$ are incident on the target. In the graph,one peak corresponds to the $K_\alpha$ line and the other peak corresponds to the $K_\beta$ line.

When a beam of accelerated electrons hits a target,a continuous $X$-ray spectrum is emitted from the target. Which of the following wavelengths is absent in the $X$-ray spectrum,if the $X$-ray tube is operating at $40,000 \ V$?

If $\lambda_{Cu}$ is the wavelength of the $K_{\alpha}$ $X$-ray line of copper (atomic number $Z = 29$) and $\lambda_{Mo}$ is the wavelength of the $K_{\alpha}$ $X$-ray line of molybdenum (atomic number $Z = 42$),then the ratio $\frac{\lambda_{Cu}}{\lambda_{Mo}}$ is close to:

Why is a direct $X$-ray photograph of the intestines not taken by a radiologist?

$X$-rays can be used to study crystal structure if the wavelength lies in the range: