Question

Two waves $A$ and $B$ have wavelength $0.01A^o$ and $9000A^o$ respectively. Name the two waves.

• A. A-gamma, B-infrared
• B. A-gamma, B-ultraviolet
• C. A-ultraviolet, B-infrared
• D. A-gamma, B-X rays

Answer 1

The correct option is A A-gamma, B-infrared

Electromagnetic radiation is classified into types according to the frequency of the wave. These types include, in order of increasing frequency, radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.
The frequency is the inverse of wavelength. Hence, in the order of increasing wavelength, the waves are Gamma rays ($<1nm$), X-rays ($1-10nm$), infra red rays ($700-{10}^{5}nm$), micro waves (${10}^5-{10}^{8}nm$), radio waves (${>10}^{8}nm$). Therefore, the range of the electromagnetic spectrum is $0.01Ato9000A$.
Hence, the wave A with wavelength of $0.01A$ is Gamma rays and the wave B with wavelength of $9000A$ is radio waves.