93 lines
3.7 KiB
Markdown
93 lines
3.7 KiB
Markdown
T0C - RF hazards: radiation exposure, proximity to antennas, recognized safe power levels, radiation types, duty cycle
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- [[T0C01]] (D)
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What type of radiation are radio signals? #card
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- A. Gamma radiation
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- B. Ionizing radiation
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- C. Alpha radiation
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- D. Non-ionizing radiation
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- [[T0C02]] (B)
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At which of the following frequencies does maximum permissible exposure have the lowest value? #card
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- A. 3.5 MHz
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- B. 50 MHz
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- C. 440 MHz
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- D. 1296 MHz
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- [[T0C03]] (C)
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How does the allowable power density for RF safety change if duty cycle changes from 100 percent to 50 percent? #card
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- A. It increases by a factor of 3
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- B. It decreases by 50 percent
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- C. It increases by a factor of 2
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- D. There is no adjustment allowed for lower duty cycle
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- [[T0C04]] (D)
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What factors affect the RF exposure of people near an amateur station antenna? #card
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- A. Frequency and power level of the RF field
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- B. Distance from the antenna to a person
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- C. Radiation pattern of the antenna
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- D. All these choices are correct
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- [[T0C05]] (D)
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Why do exposure limits vary with frequency? #card
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- A. Lower frequency RF fields have more energy than higher frequency fields
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- B. Lower frequency RF fields do not penetrate the human body
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- C. Higher frequency RF fields are transient in nature
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- D. The human body absorbs more RF energy at some frequencies than at others
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- [[T0C06]] (D)
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Which of the following is an acceptable method to determine whether your station complies with FCC RF exposure regulations? #card
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- A. By calculation based on FCC OET Bulletin 65
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- B. By calculation based on computer modeling
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- C. By measurement of field strength using calibrated equipment
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- D. All these choices are correct
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- [[T0C07]] (B)
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What hazard is created by touching an antenna during a transmission? #card
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- A. Electrocution
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- B. RF burn to skin
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- C. Radiation poisoning
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- D. All these choices are correct
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- [[T0C08]] (A)
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Which of the following actions can reduce exposure to RF radiation? #card
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- A. Relocate antennas
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- B. Relocate the transmitter
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- C. Increase the duty cycle
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- D. All these choices are correct
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- [[T0C09]] (B)
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How can you make sure your station stays in compliance with RF safety regulations? #card
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- A. By informing the FCC of any changes made in your station
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- B. By re-evaluating the station whenever an item in the transmitter or antenna system is changed
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- C. By making sure your antennas have low SWR
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- D. All these choices are correct
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- [[T0C10]] (A)
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Why is duty cycle one of the factors used to determine safe RF radiation exposure levels? #card
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- A. It affects the average exposure to radiation
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- B. It affects the peak exposure to radiation
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- C. It takes into account the antenna feed line loss
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- D. It takes into account the thermal effects of the final amplifier
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- [[T0C11]] (C)
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What is the definition of duty cycle during the averaging time for RF exposure?
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- A. The difference between the lowest power output and the highest power output of a transmitter
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- B. The difference between the PEP and average power output of a transmitter
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- C. The percentage of time that a transmitter is transmitting
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- D. The percentage of time that a transmitter is not transmitting
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- [[T0C12]] (A)
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How does RF radiation differ from ionizing radiation (radioactivity)? #card
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- A. RF radiation does not have sufficient energy to cause chemical changes in cells and damage DNA
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- B. RF radiation can only be detected with an RF dosimeter
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- C. RF radiation is limited in range to a few feet
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- D. RF radiation is perfectly safe
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- [[T0C13]] (B)
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Who is responsible for ensuring that no person is exposed to RF energy above the FCC exposure limits? #card
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- A. The FCC
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- B. The station licensee
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- C. Anyone who is near an antenna
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- D. The local zoning board
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