What color do we see when fields oscillate at 500 trillion times per second?

What color do we see when fields oscillate at 500 trillion times per second?

• A. Red
• B. Yellow
• C. Green
• D. Blue

Answer: (B)

Color depends on the light’s frequency (or its wavelength): higher frequency means shorter wavelength and a shift along the visible spectrum from red toward violet. A frequency of 500 trillion cycles per second is about 5×10^14 Hz, which lies in the visible range near wavelengths around 600 nm. That region is typically described as yellow (right at the yellow–orange boundary in many color charts). So, the light would be perceived as yellow. If the frequency were lower, red would be seen; if higher, green, blue, or violet would appear.

Color depends on the light’s frequency (or its wavelength): higher frequency means shorter wavelength and a shift along the visible spectrum from red toward violet. A frequency of 500 trillion cycles per second is about 5×10^14 Hz, which lies in the visible range near wavelengths around 600 nm. That region is typically described as yellow (right at the yellow–orange boundary in many color charts). So, the light would be perceived as yellow. If the frequency were lower, red would be seen; if higher, green, blue, or violet would appear.