Question

An electromagnetic radiation has an energy 11 Kev. To which region of electromagnetic spectrum does it belong? use : $\left( h =6.6 \times 10^{-34} Js , e =1.6 \times 10^{-19} C \right)$

• A. Infrared
• B. Microwave
• C. X-ray
• D. Y-rays

Answer 1

Answer: (C)

$E =11 KeV =11 \times 10^{3} \times 1.6 \times 10^{-19}$
$11 \times 10^{-16} \times 1.6=\frac{ hc }{\lambda}$
$\lambda=\frac{6.6 \times 10^{-34} \times 3 \times 10^{8}}{1.6 \times 11 \times 10^{-16}}=1.125 \times 10^{-10} m$
$\lambda=1.125 \mathring{A}$
This wavelength lies in the region of X-ray