Over what range of frequencies are the FCC human body RF exposure limits most restrictive?
300 kHz - 3 MHz
3 - 30 MHz
30 - 300 MHz✓الإجابة الصحيحة
300 - 3000 MHz
الشرح
The permitted levels are lowest across 30 to 300 MHz, the range in which an adult human body is near whole-body resonance and therefore absorbs RF energy most efficiently, so a given field strength deposits the most power in tissue. Both exposure tiers bottom out in that row of the limits table, at 0.2 milliwatts per square centimeter for the general population and 1.0 for occupational exposure, against 1.0 and 5 respectively above 1500 MHz.