Question
When a beam of accelerated electrons hits a target, a continuous X-ray spectrum is emitted from the target. Which of the following wavelength is absent in the X-ray spectrum, if the X-ray tube is operating at 40,000 volts(a) 0.25 Å(b) 0.5 Å(c) 1.5 Å  (d) 1.0 Å
       

Answer

(a) 0.25 Å

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