Arrange the following electromagnetic waves in the increasing order of their frequencies.
A. Microwaves
B. Ultraviolet waves
C. X-rays
D. Visible light
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A, D, B, C
Across the electromagnetic spectrum, frequency increases as wavelength decreases: radio, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays.
\( \text{Microwaves (A)}: \sim 10^{9}\text{ to }10^{11}\,\mathrm{Hz} \)
\( \text{Visible light (D)}: \sim 4\times10^{14}\text{ to }8\times10^{14}\,\mathrm{Hz} \)
\( \text{Ultraviolet waves (B)}: \sim 10^{15}\text{ to }10^{17}\,\mathrm{Hz} \)
\( \text{X-rays (C)}: \sim 10^{17}\text{ to }10^{19}\,\mathrm{Hz} \)
In increasing order of frequency: A, D, B, C.
NCERT (2026-27):
Electromagnetic Spectrum – “… We briefly describe these different types of electromagnetic waves, in order of decreasing wavelengths.”
Microwaves – “Microwaves (short-wavelength radio waves), with frequencies in the gigahertz (GHz) range, are produced by special vacuum tubes (called klystrons, magnetrons and Gunn diodes).”
Visible Rays – “… It runs from about 4 × 1014 Hz to about 7 × 1014 Hz or a wavelength range of about 700 – 400 nm.”
Ultraviolet Rays – “It covers wavelengths ranging from about 4 × 10–7 m (400 nm) down to 6 × 10–10 m (0.6 nm).”
X-Rays – “Beyond the UV region of the electromagnetic spectrum lies the X-ray region.”