Question

Find the cutoff wavelength for the continuous X-rays coming from an X-ray tube operating at 30 kV.

Answer 1

Given:
Voltage of the X-ray tube, V = 30 kV
Cutoff wavelength for continuous X-rays $\left(\lambda \right)$ is given by
$$\begin{gathered} \lambda =\frac{hc}{e\mathrm{V}} \\ \mathrm{Here}, \\ h=\mathrm{Planck}\text{'}s\mathrm{constant} \\ V=\mathrm{Voltage}\mathrm{of}\mathrm{the}\mathrm{X}-\mathrm{ray}\mathrm{tube} \\ c=\mathrm{Speed}\mathrm{of}\mathrm{light} \\ \therefore \lambda =\frac{1242\mathrm{eV}-\mathrm{nm}}{\mathrm{e}\times 30\times {10}^3} \\ \Rightarrow \lambda =414\times {10}^{-4}\mathrm{nm}=41.4\mathrm{pm} \end{gathered}$$