Arrange the following electromagnetic waves in decreasing order of their respective wavelengths.
(A) UV-rays
(B) X-rays
(C) Radio waves
(D) Visible light
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (C)>(D)>(A)>(B)
The electromagnetic spectrum, in order of decreasing wavelength, runs from radio waves through microwaves, infra-red, visible light and ultraviolet to X-rays and gamma rays. A longer wavelength means a lower frequency and a lower photon energy.
\( (C)\ \text{Radio waves}: \lambda \gt 0.1\,\mathrm{m} \)
\( (D)\ \text{Visible light}: 400\text{ to }700\,\mathrm{nm} \)
\( (A)\ \text{UV-rays}: 1\text{ to }400\,\mathrm{nm} \)
\( (B)\ \text{X-rays}: 10^{-3}\text{ to }1\,\mathrm{nm} \)
So the decreasing order of wavelength is radio waves, visible light, UV-rays, X-rays, that is (C) > (D) > (A) > (B).
NCERT (2026-27):
Gamma Rays – …
