Which of the following best describes the fraction of the entire electromagnetic spectrum that is spanned by visible light?

• A. A very small fraction
• B. A large fraction
• C. Nearly the entire spectrum
• D. About half of the spectrum

Answer: (A)

Verified step by step guidance

1. Understand that the electromagnetic spectrum includes all types of electromagnetic radiation, ranging from gamma rays with very short wavelengths to radio waves with very long wavelengths.
2. Recognize that visible light is the portion of the electromagnetic spectrum that human eyes can detect, typically ranging from about 400 nm (violet) to 700 nm (red) in wavelength.
3. Compare the wavelength range of visible light to the entire electromagnetic spectrum, which spans many orders of magnitude beyond the visible range, including ultraviolet, infrared, X-rays, microwaves, and radio waves.
4. Note that because the visible light range is very narrow compared to the full spectrum, it represents only a tiny fraction of the total electromagnetic spectrum.
5. Conclude that the fraction of the electromagnetic spectrum spanned by visible light is best described as 'a very small fraction.'