Technician exam question T0C05
Subelement T0, SAFETY· Group T0C
Why do exposure limits vary with frequency?
- A.Lower frequency RF fields have more energy than higher frequency fields
- B.Lower frequency RF fields do not penetrate the human body
- C.Higher frequency RF fields are transient in nature
- D.The human body absorbs more RF energy at some frequencies than at others (correct answer)
WhyExposure limits vary with frequency because the human body absorbs more RF energy at some frequencies than at others. The human body absorbs RF energy more or less efficiently depending on frequency, with absorption peaking around frequencies where the body (or a body part) acts like a natural antenna, which is exactly why the FCC sets different exposure limits at different frequencies, answer D. Lower frequency fields don't inherently carry more energy than higher ones (A, energy per photon actually increases with frequency), lower frequencies do still penetrate the body somewhat (B), and higher frequency fields aren't described as "transient" in this context (C).
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.
Related questions
- T0C01What type of radiation are radio signals?
- T0C02Which of the following bands has the lowest maximum permissible exposure for RF safety?
- T0C03How does the allowable power density for RF safety change if duty cycle changes from 100 percent to 50 percent?
- T0C04What factors affect the RF exposure of people near an amateur station antenna?
- T0C06Which of the following is an acceptable method to determine whether your station complies with FCC RF exposure regulations?