FCC Technician Class Exam Study Guide - 2014-2018/Subelement T0 Group C
Question
[edit | edit source]Introduction
[edit | edit source]T0C - RF hazards: radiation exposure; proximity to antennas; recognized safe power levels; exposure to others; radiation types; duty cycle
The Question Pool
[edit | edit source]Question 1
[edit | edit source]- What type of radiation are VHF and UHF radio signals?
- A. Gamma radiation
- B. Ionizing radiation
- C. Alpha radiation
- D. Non-ionizing radiation
The correct answer is D.
Question 2
[edit | edit source]- Which of the following frequencies has the lowest value for Maximum Permissible Exposure limit?
- A. 3.5 MHz
- B. 50 MHz
- C. 440 MHz
- D. 1296 MHz
The correct answer is B.
Question 3
[edit | edit source]- What is the maximum power level that an amateur radio station may use at VHF frequencies before an RF exposure evaluation is required?
- A. 1500 watts PEP transmitter output
- B. 1 watt forward power
- C. 50 watts PEP at the antenna
- D. 50 watts PEP reflected power
The correct answer is C.
Question 4
[edit | edit source]- What factors affect the RF exposure of people near an amateur station antenna?
- A. Frequency and power level of the RF field
- B. Distance from the antenna to a person
- C. Radiation pattern of the antenna
- D. All of these choices are correct
The correct answer is D.
Question 5
[edit | edit source]- 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
The correct answer is D.
Question 6
[edit | edit source]- Which of the following is an acceptable method to determine that your station complies with FCC RF exposure regulations?
- A. By calculation based on FCC OET Bulletin 65
- B. By calculation based on computer modeling
- C. By measurement of field strength using calibrated equipment
- D. All of these choices are correct
The correct answer is D.
Question 7
[edit | edit source]- What could happen if a person accidentally touched your antenna while you were transmitting?
- A. Touching the antenna could cause television interference
- B. They might receive a painful RF burn
- C. They might develop radiation poisoning
- D. All of these choices are correct
The correct answer is B.
Question 8
[edit | edit source]- Which of the following actions might amateur operators take to prevent exposure to RF radiation in excess of FCC-supplied limits?
- A. Relocate antennas
- B. Relocate the transmitter
- C. Increase the duty cycle
- D. All of these choices are correct
The correct answer is A.
Question 9
[edit | edit source]- How can you make sure your station stays in compliance with RF safety regulations?
- A. By informing the FCC of any changes made in your station
- B. By re-evaluating the station whenever an item of equipment is changed
- C. By making sure your antennas have low SWR
- D. All of these choices are correct
The correct answer is B.
Question 10
[edit | edit source]- Why is duty cycle one of the factors used to determine safe RF radiation exposure levels?
- A. It affects the average exposure of people to radiation
- B. It affects the peak exposure of people to radiation
- C. It takes into account the antenna feed line loss
- D. It takes into account the thermal effects of the final amplifier
The correct answer is A.
Question 11
[edit | edit source]- What is the definition of duty cycle during the averaging time for RF exposure?
- A. The difference between the lowest power output and the highest power output of a transmitter
- B. The difference between the PEP and average power output of a transmitter
- C. The percentage of time that a transmitter is transmitting
- D. The percentage of time that a transmitter is not transmitting
The correct answer is C.
Question 12
[edit | edit source]- How does RF radiation differ from ionizing radiation (radioactivity)?
- A. RF radiation does not have sufficient energy to cause genetic damage
- B. RF radiation can only be detected with an RF dosimeter
- C. RF radiation is limited in range to a few feet
- D. RF radiation is perfectly safe
The correct answer is A.
Question 13
[edit | edit source]- If the averaging time for exposure is 6 minutes, how much power density is permitted if the signal is present for 3 minutes and absent for 3 minutes rather than being present for the entire 6 minutes?
- A. 3 times as much
- B. 1/2 as much
- C. 2 times as much
- D. There is no adjustment allowed for shorter exposure times
The correct answer is C.