Arrange the following EM waves in decreasing order of their wavelengt…

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

The electromagnetic spectrum runs, in decreasing wavelength, as radio → microwaves → infrared → visible → ultraviolet → X-rays → gamma rays.

    \( \text{(A) Microwaves: about 1 mm to 0.3 m} \)
    \( \text{(C) Yellow light: about 580 nm} \)
    \( \text{(B) Ultraviolet radiations: about 1 nm to 400 nm} \)
    \( \text{(D) X-rays: about 0.01 nm to 10 nm} \)

Decreasing order of wavelength:

    \( \text{(A)} \gt \text{(C)} \gt \text{(B)} \gt \text{(D)} \)

NCERT (2026-27):
Electromagnetic Spectrum – “… We briefly describe these different types of electromagnetic waves, in order of decreasing wavelengths.”

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 – “… It covers wavelengths from about 10^–8 m (10 nm) down to 10^–13 m (10^–4 nm).”