General G0A: RF exposure
These are the 12 official questions in group G0A of the 2023–2027 General question pool, with the correct answer marked and a plain-English explanation of why it's right. The real exam asks one question from this group.
- G0A01Question 1
What is one way that RF energy can affect human body tissue?
- AIt heats body tissue Correct
- BIt causes radiation poisoning
- CIt causes the blood count to reach a dangerously low level
- DIt cools body tissue
Why: RF energy heats body tissue.
- G0A02Question 2
Which of the following is used to determine RF exposure from a transmitted signal?
- AIts duty cycle
- BIts frequency
- CIts power density
- DAll these choices are correct Correct
Why: Power, frequency, antenna gain and pattern, and distance all determine exposure. All the choices are correct.
- G0A03Question 3FCC 97.13(c)(1)
How can you determine that your station complies with FCC RF exposure regulations?
- ABy calculation based on FCC OET Bulletin 65
- BBy calculation based on computer modeling
- CBy measurement of field strength using calibrated equipment
- DAll these choices are correct Correct
Why: Calculations, modeling and measurements are all acceptable ways to show compliance. All the choices are correct.
- G0A04Question 4
What does “time averaging” mean when evaluating RF radiation exposure?
- AThe average amount of power developed by the transmitter over a specific 24-hour period
- BThe average time it takes RF radiation to have any long-term effect on the body
- CThe total time of the exposure
- DThe total RF exposure averaged over a certain period Correct
Why: Time averaging means total exposure averaged over a set period.
- G0A05Question 5FCC 97.13(c)(2), 1.1307(b)
What must you do if an evaluation of your station shows that the RF energy radiated by your station exceeds permissible limits for possible human absorption?
- ATake action to prevent human exposure to the excessive RF fields Correct
- BFile an Environmental Impact Statement (EIS-97) with the FCC
- CSecure written permission from your neighbors to operate above the controlled MPE limits
- DAll these choices are correct
Why: If your station exceeds the limits, take action to prevent people from being exposed.
- G0A06Question 6FCC 97.13(c)(2), 1.1307(1)(b)(3)(i)
What must you do if your station fails to meet the FCC RF exposure exemption criteria?
- APerform an RF exposure evaluation in accordance with FCC OET Bulletin 65 Correct
- BContact the FCC for permission to transmit
- CPerform an RF exposure evaluation in accordance with World Meteorological Organization guidelines
- DUse an FCC-approved band-pass filter
Why: If you're not exempt, do an evaluation per FCC OET Bulletin 65.
- G0A07Question 7
What is the effect of modulation duty cycle on RF exposure?
- AA lower duty cycle permits greater power levels to be transmitted Correct
- BA higher duty cycle permits greater power levels to be transmitted
- CLow duty cycle transmitters are exempt from RF exposure evaluation requirements
- DHigh duty cycle transmitters are exempt from RF exposure requirements
Why: A lower duty cycle allows higher power for the same average exposure.
- G0A08Question 8FCC 97.13(c)(2)
Which of the following steps must an amateur operator take to ensure compliance with RF safety regulations?
- APost a copy of FCC Part 97.13 in the station
- BNotify neighbors within a 100-foot radius of the antenna of the existence of the station and power levels
- CPerform a routine RF exposure evaluation and prevent access to any identified high exposure areas Correct
- DAll these choices are correct
Why: Do routine evaluations and block access to high-exposure areas.
- G0A09Question 9
What type of instrument can be used to accurately measure an RF field strength?
- AA receiver with digital signal processing (DSP) noise reduction
- BA calibrated field strength meter with a calibrated antenna Correct
- CAn SWR meter with a peak-reading function
- DAn oscilloscope with a high-stability crystal marker generator
Why: A calibrated field strength meter with a calibrated antenna measures RF fields accurately.
- G0A10Question 10
What should be done if evaluation shows that a neighbor might experience more than the allowable limit of RF exposure from the main lobe of a directional antenna?
- AChange to a non-polarized antenna with higher gain
- BUse an antenna with a higher front-to-back ratio
- CTake precautions to ensure that the antenna cannot be pointed in their direction when they are present Correct
- DAll these choices are correct
Why: Make sure the antenna can't point at the neighbor while they're present.
- G0A11Question 11
What precaution should be taken if you install an indoor transmitting antenna?
- ALocate the antenna close to your operating position to minimize feed-line radiation
- BPosition the antenna along the edge of a wall to reduce parasitic radiation
- CMake sure that MPE limits are not exceeded in occupied areas Correct
- DMake sure the antenna is properly shielded
Why: Make sure MPE limits aren't exceeded in occupied areas.
- G0A12Question 12FCC 1.1307(1)(b)(3)(i)(A)
What stations are subject to the FCC rules on RF exposure?
- AAll commercial stations; amateur radio stations are exempt
- BOnly stations with antennas lower than one wavelength above the ground
- COnly stations transmitting more than 500 watts PEP
- DAll stations with a time-averaged transmission of more than one milliwatt Correct
Why: Any station averaging more than 1 milliwatt is covered.