Question

An X-ray tube is operated at a constant potential difference and it is required to get an X-ray of wavelength not less than 0.2 nano-metres. Then the potential difference in kilovolts is $(h=6.63\times {10}^{-34}Js;e=1.6\times {10}^{-19}C;c=3\times {10}^{8}m{s}^{-1}$)

• A. 24.8
• B. 12.4
• C. 6.2
• D. 3.1

Answer 1

Answer: (C)

6.2

Potential difference =$\left(\frac{hc}{\lambda }\right)le$

=$\frac{6.63\times {10}^{-34}\times 3\times {10}^8}{0.2\times {10}^{-9}\times 1.6\times {10}^{-19}}$
=$62\times {10}^{2}V$
=$6.2\times {10}^{3}V$
=6.2 KV.