The U.S. Food and Drug Administration limits the radiation leakage of microwave ovens to no more than 5.0 m W/cm2 at a distance of 2.00 in. A typical cell phone, which also transmits microwaves, has a peak output power of about 2.0 W.
a) Approximating the cell phone as a point source, calculate the radiation intensity of a cell phone at a distance of 2.00 in. How does the answer compare by the maximum allowable microwave oven leakage?
b) The distance from your ear to your brain is about 2 in. What would the radiation intensity in your brain be if you utilized a Bluetooth headset, keeping the phone in your pocket, 1.0 m away from your brain? Most headsets are so-called Class 2 devices by a maximum output power of 2.5 mW.