Question

Monochromatic X-rays of wavelength $0.12A^o$ undergo Compton scattering through an angle ${60}^o$ from a carbon block. The wavelength of the scattered X-rays, in $A^o(Take\frac{h}{m_{o}c}=0.024A^o)$

• A. 0.112
• B. 0.132
• C. 0.156
• D. 0.182

Answer 1

Answer: (B)

0.132

By compton formula
$\Delta \lambda ={\lambda }_f-{\lambda }_i=\frac{h}{m_{e}c}(1-cos\theta )$

${\lambda }_f-0.12A^{\circ }=0.024-A^{\circ }(1-cos{60}^{\circ })$

${\lambda }_f=0.12A^{\circ }+0.024A^{\circ }(1-\frac{1}{2})(\because cos{60}^{\circ }=1/2)$

$=0.12A^{\circ }+\frac{0.024}{2}{A}^{\circ }$

$=0.12A^{\circ }+0.024A^{\circ }$
$=0.132A^{\circ }.$

So, the answer is option (B).