Change set

Pick exam & year, then Go.

Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q18 (CDS-II/2018) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Waves and acoustics Answer Verified

The visible portion of the electromagnetic spectrum is

Result
Your answer: —  Â·  Correct: D
Explanation

The electromagnetic (EM) spectrum encompasses a wide range of radiation types, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays [5]. Among these, the visible portion is specifically defined as the narrow band of electromagnetic radiation that the human eye can detect, typically ranging from 400 to 700 nm [3]. While other forms of radiation like infrared and microwaves are part of the EM spectrum, they are invisible to the human eye. Light is often used as a synonym for this visible region, though in broader scientific contexts, 'optical radiation' may also include ultraviolet and infrared [1]. The visible spectrum is unique because it is the only region that enables human vision and is responsible for phenomena like the colors of a rainbow [4]. Therefore, 'light' is the correct term for the visible portion of the spectrum.

Sources

  1. [2] https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
  2. [5] https://en.wikipedia.org/wiki/Electromagnetic_spectrum
  3. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC8887026/
  4. [3] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > p. 134
  5. [4] https://www.sciencedirect.com/topics/physics-and-astronomy/visible-spectrum
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
47%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

5 Cross-Linked PYQs

UPSC repeats concepts across years. Login to see how this question connects to 5 others.

Login with Google