Imagine that a beam of blue light has its wavelength doubled to yield light in the infrared region of the electromagnetic spectrum. Would you have to increase or decrease the frequency of this infrared radiation to obtain the blue light back again?

Question

anonymous · Answer

Increase since you doubled the wavelength to create the infrared light. Wavelength and frequency are inversely proportional- as one gets larger, the other gets smaller.

anonymous · Answer

When you obtained the infrared light, you decreased the frequency. So, you have to increase frequency to get to the higher energy visible light.