Question

An electromagnetic radiation has an energy of 13.2 keV. Then the radiation belongs to the region of

• A. visible light
• B. ultraviolet
• C. infrared
• D. X-ray

Answer 1

Answer: (D)

X-ray

Given : E = 13.2 keV

The wavelength of the radiation is given by;

$\lambda \left(in\stackrel{o}{A}\right)=\frac{hc}{E\left(ineV\right)}$

$=\frac{12400}{13.2\times {10}^3}=0.939\stackrel{o}{A}\approx 1\stackrel{o}{A}$

X-rays cover wavelengths ranging from about ${10}^{-8}m\left(10nm\right)$ to ${10}^{-13}m\left({10}^{-4}nm\right)$.

Electromagnetic radiation of energy 13.2 keV belongs to X-ray region of the electromagnetic spectrum.