# X-rays of energy 50 KeV and scattered from a carbon target. The scattered rays are deleted at $90^{\circ}$ from the innocent beam. The percentage changes in wavelength approximately $[m_e= 9.0 \times 10^{-31}kg, c= 3 \times 19^8 m/sec]$ is

$\begin {array} {1 1} (1)\;10 \% & \quad (2)\;20 \% \\ (3)\;5 \% & \quad (4)\;1 \% \end {array}$

$(1) 10 \%$
answered Nov 7, 2013 by