FCC Technician Class Exam Study Guide - 2014-2018/Subelement T0 Group C

Introduction
T0C - RF hazards: radiation exposure; proximity to antennas; recognized safe power levels; exposure to others; radiation types; duty cycle

Question 1

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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

 * 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.