To which part of the electromagnetic spectrum does a wavelength of \( 3.1\times10^{-14}\,\mathrm{m} \) belong?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Gamma rays
The regions of the electromagnetic spectrum are named by their wavelength range. Expressed in nanometres, the given wavelength is
\( \lambda=3.1\times10^{-14}\,\mathrm{m}=3.1\times10^{-5}\,\mathrm{nm} \)
This is far shorter than \( 10^{-3}\,\mathrm{nm} \), the lower end of the X-ray band.
Option (1) Microwaves — Incorrect. Microwaves have wavelengths from 0.1 m to 1 mm.
Option (2) Ultraviolet rays — Incorrect. Ultraviolet rays run from 400 nm down to about 1 nm.
Option (3) Gamma rays — Correct. Gamma rays have the shortest wavelengths, below \( 10^{-3}\,\mathrm{nm} \), and \( 3.1\times10^{-5}\,\mathrm{nm} \) lies in this band.
Option (4) Radio waves — Incorrect. Radio waves have the longest wavelengths, more than 0.1 m.
NCERT (2026-27):
Electromagnetic Spectrum
