What is the approximate frequency range of visible light?

What is the approximate frequency range of visible light?

• A. About 1×10^6 to 1×10^7 Hz
• B. About 4×10^14 to 7×10^14 Hz
• C. About 1×10^9 to 1×10^10 Hz
• D. About 1×10^16 to 1×10^17 Hz

Answer: (B)

Visible light sits in a narrow band of frequencies. Using the speed of light and typical visible wavelengths, roughly 380 to 750 nanometers, the frequency f = c/λ gives about 4×10^14 Hz for the red end and about 7×10^14 Hz for the violet end. So the approximate range is 4×10^14 to 7×10^14 Hz. The other options lie outside this band: 10^6–10^7 Hz are radio waves, 10^9–10^10 Hz are still far below visible, and 10^16–10^17 Hz correspond to ultraviolet and higher-energy photons.

Visible light sits in a narrow band of frequencies. Using the speed of light and typical visible wavelengths, roughly 380 to 750 nanometers, the frequency f = c/λ gives about 4×10^14 Hz for the red end and about 7×10^14 Hz for the violet end. So the approximate range is 4×10^14 to 7×10^14 Hz.

The other options lie outside this band: 10^6–10^7 Hz are radio waves, 10^9–10^10 Hz are still far below visible, and 10^16–10^17 Hz correspond to ultraviolet and higher-energy photons.