Question

An X-ray tube operates at a potential difference of 24824 V. The minimum wavelength of X-rays emitted by this tube is (nearly)

• A. 24.8 $A^o$
• B. 0.5 $A^o$
• C. 1 $A^o$
• D. 2 $A^o$

Answer 1

The correct option is B 0.5 $A^o$

$Energy=p.d\times e$
$=24824\times e$
$=24824eV$
$energy=\frac{hc}{\lambda }$
$\lambda =\frac{hc}{energy}$
$=\frac{1240eV-nm}{24824eV}$ $(hc=1240eV-nm)$

$=0.05nm$
$=0.5A^{\circ }$

So, the answer is option (B).