A television remote control uses an infrared light-emitting diode (LED) that emits…
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
A television remote control uses an infrared light-emitting diode (LED) that emits radiation with a wavelength of 940nm. Engineers wish to compare this device with a proposed redesign that would use visible red light instead.
(a) Identify the region of the electromagnetic spectrum associated with the 940nm radiation.
(b) Calculate the frequency corresponding to this wavelength.
(c) Give two reasons why manufacturers typically choose the region identified in part (a), rather than visible light, for consumer remote controls. Provide a brief physical justification for each reason.
(d) Describe one practical drawback, rooted in electromagnetic-wave properties, that might arise if the redesign used visible red light instead of the original radiation.