Electrons with de-Broglie wavelength λ fall on the target in an X-ray tube. The cut-off wavelength of the emitted X-rays is [2007]
(1)
The cut-off wavelength of the emitted X-ray,
λ0=hceV ⋯(i)
According to de Broglie equation,
λ=hp=h2meV
or λ2=h22meV⇒V=h22meλ2 ⋯(ii)
From eq. (i) and (ii),
λ0=hc×2meλ2eh2=2mcλ2h