Arrange the following electromagnetic waves in the ascending order of…

The correct answer is Option (2) → (B), (D), (C), (A)

In the electromagnetic spectrum the wavelength increases in the order gamma rays, X-rays, ultraviolet, visible, infrared, microwaves, radio waves.

    \( \text{Gamma rays: shorter than about } 10^{-3}\,\mathrm{nm} \)
    \( \text{Ultraviolet: about } 1\,\mathrm{nm} \text{ to } 400\,\mathrm{nm} \)
    \( \text{Infrared: about } 1\,\mathrm{mm} \text{ to } 700\,\mathrm{nm} \)
    \( \text{Radio waves: longer than about } 0.1\,\mathrm{m} \)

So in ascending order of wavelength: (B) gamma rays \( \lt \) (D) ultraviolet \( \lt \) (C) infrared \( \lt \) (A) radio waves.

The order is B, D, C, A.

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.”