Technician T0C: RF exposure safety
These are the 13 official questions in group T0C of the 2026–2030 Technician 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.
- T0C01Question 1
What type of radiation are radio signals?
- AGamma radiation
- BIonizing radiation
- CAlpha radiation
- DNon-ionizing radiation Correct
Why: Radio signals are non-ionizing radiation.
- T0C02Question 2
Which of the following bands has the lowest maximum permissible exposure for RF safety?
- A3.5 MHz
- B50 MHz Correct
- C440 MHz
- D1296 MHz
Why: The strictest exposure limits are from 30 to 300 MHz, so 50 MHz has the lowest limit of the choices.
- T0C03Question 3
How does the allowable power density for RF safety change if duty cycle changes from 100 percent to 50 percent?
- AIt increases by a factor of 3
- BIt decreases by 50 percent
- CIt increases by a factor of 2 Correct
- DThere is no adjustment allowed for lower duty cycle
Why: Halving the duty cycle halves the average exposure, so the allowed power density doubles.
- T0C04Question 4
What factors affect the RF exposure of people near an amateur station antenna?
- AFrequency and power level of the RF field
- BDistance from the antenna to a person
- CRadiation pattern of the antenna
- DAll these choices are correct Correct
Why: Frequency, power, distance and the antenna pattern all affect exposure. All the choices are correct.
- T0C05Question 5
Why do exposure limits vary with frequency?
- ALower frequency RF fields have more energy than higher frequency fields
- BLower frequency RF fields do not penetrate the human body
- CHigher frequency RF fields are transient in nature
- DThe human body absorbs more RF energy at some frequencies than at others Correct
Why: The body absorbs RF more at some frequencies than others, so the limits vary.
- T0C06Question 6
Which of the following is an acceptable method to determine whether 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: FCC tables, computer modeling and field measurements are all acceptable. All the choices are correct.
- T0C07Question 7
What hazard is created by touching an antenna during a transmission?
- AElectrocution
- BRF burn to skin Correct
- CExposure to ionizing radiation
- DAll these choices are correct
Why: Touching a transmitting antenna can cause an RF burn.
- T0C08Question 8
Which of the following actions can reduce exposure to RF radiation?
- ARelocate antennas Correct
- BRelocate the transmitter
- CIncrease the duty cycle
- DAll these choices are correct
Why: Moving the antenna farther from people reduces their exposure.
- T0C09Question 9
How can you make sure your station stays in compliance with RF safety regulations?
- ABy informing the FCC of any changes made in your station
- BBy re-evaluating the station whenever an item in the transmitter or antenna system is changed Correct
- CBy making sure your antennas have low SWR
- DBy using only Underwriter Laboratories approved transmitting equipment
Why: Re-evaluate whenever anything in the transmitter or antenna system changes.
- T0C10Question 10
Why is duty cycle one of the factors used to determine safe RF radiation exposure levels?
- AIt affects the average exposure to radiation Correct
- BIt affects the peak exposure to radiation
- CIt takes into account the antenna feed line loss
- DIt takes into account the thermal effects of the final amplifier
Why: Duty cycle changes the average exposure over time.
- T0C11Question 11
What is the definition of duty cycle during the averaging time for RF exposure?
- AThe difference between the lowest and highest power output of a transmitter
- BThe difference between the PEP and the average power output of a transmitter
- CThe percentage of time that a transmitter is transmitting Correct
- DThe percentage of time that a transmitter is not transmitting
Why: Duty cycle is the percentage of time the transmitter is transmitting.
- T0C12Question 12
How does RF radiation differ from ionizing radiation (radioactivity)?
- ARF radiation does not have sufficient energy to cause chemical changes in cells and damage DNA Correct
- BRF radiation can only be detected with an RF dosimeter
- CRF radiation is limited in range to a few feet
- DRF radiation is perfectly safe
Why: RF doesn't have enough energy to cause chemical changes in cells or damage DNA.
- T0C13Question 13
Who is responsible for ensuring that no person is exposed to RF energy above the FCC exposure limits?
- AThe FCC
- BThe station licensee Correct
- CAnyone who is near an antenna
- DThe local zoning board
Why: The station licensee is responsible for keeping people below the exposure limits.