Question

The shortest wavelength of $X$-rays coming from an $X$-ray tube depends on the

• A. voltage applied to the tube
• B. current in the tube
• C. atomic number of target element
• D. nature of gas in the tube

Answer 1

Answer: (A)

voltage applied to the tube

Answer 2

When the electron loses whole of its energy in a single collision with the atoms, an $X$-ray photon of maximum energy $h_{\max }$ is emitted ie, $\frac{1}{2} m v^{2}=e V$ $=h v_{\max }=\frac{h c}{\lambda_{\min }}$ Minimum wavelength = cut-off wavelength of $X$-ray $\lambda_{\min }=\frac{h c}{e V}=\frac{12375}{V_{(\text {in out })}} \,�$