Arrange the following em waves in the order of their increasing wavel…

The correct answer is Option (4) → C<D<A<B

The electromagnetic spectrum runs from the longest wavelengths (radio waves) to the shortest (gamma rays), with microwaves, infrared, visible light, ultraviolet and X-rays in between.

    (C) Gamma rays: less than \( 10^{-3}\,\mathrm{nm} \)

    (D) Ultraviolet rays: \( 400\,\mathrm{nm} \) to \( 1\,\mathrm{nm} \)

    (A) Visible light: \( 700\,\mathrm{nm} \) to \( 400\,\mathrm{nm} \)

    (B) Radio waves: more than \( 0.1\,\mathrm{m} \)

The order of increasing wavelength is therefore C < D < A < B.

NCERT (2026-27):
Summary – “… 6. The spectrum of electromagnetic waves stretches, in principle, over an infinite range of wavelengths. Different regions are known by different names; γ-rays, X-rays, ultraviolet rays, visible rays, infrared rays, microwaves and radio waves in order of increasing wavelength from 10^–2 Å or 10^–12 m to 10⁶ m.”