Extra-Study/pages/E0A.md

E0A Safety: RF radiation hazards; hazardous materials; grounding

• E0A01 (B) What is the primary function of an external earth connection or ground rod? #card
  • A. Prevent static build up on power lines
  • B. Lightning charge dissipation
  • C. Reduce RF current flow between pieces of equipment
  • D. Protect breaker panel from power surges
• E0A02 (B) When evaluating RF exposure levels from your station at a neighbor’s home, what must you do? #card
  • A. Ensure signals from your station are less than the controlled maximum permissible exposure (MPE) limits
  • B. Ensure signals from your station are less than the uncontrolled maximum permissible exposure (MPE) limits
  • C. Ensure signals from your station are less than the controlled maximum permissible emission (MPE) limits
  • D. Ensure signals from your station are less than the uncontrolled maximum permissible emission (MPE) limits
• E0A03 (C) Over what range of frequencies are the FCC human body RF exposure limits most restrictive? #card
  • A. 300 kHz - 3 MHz
  • B. 3 - 30 MHz
  • C. 30 - 300 MHz
  • D. 300 - 3000 MHz
• E0A04 (C) When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations? #card
  • A. Each transmitter that produces 20 percent or more of its MPE limit in areas where the total MPE limit is exceeded
  • B. Each transmitter operating with a duty cycle greater than 25 percent
  • C. Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded
  • D. Each transmitter operating with a duty cycle greater than 50 percent
• E0A05 (B) What hazard is created by operating at microwave frequencies? #card
  • A. Microwaves are ionizing radiation
  • B. The high gain antennas commonly used can result in high exposure levels
  • C. Microwaves are in the frequency range where wave velocity is higher
  • D. The extremely high frequency energy can damage the joints of antenna structures
• E0A06 (D) Why are there separate electric (E) and magnetic (H) MPE limits at frequencies below 300 MHz? #card
  • A. The body reacts to electromagnetic radiation from both the E and H fields
  • B. Ground reflections and scattering cause the field strength to vary with location
  • C. E field and H field radiation intensity peaks can occur at different locations
  • D. All these choices are correct
• E0A07 (B) What is meant by “100% tie-off” regarding tower safety? #card
  • A. All loose ropes and guys secured to a fixed structure
  • B. At least one lanyard attached to the tower at all times
  • C. All tools secured to the climber’s harness
  • D. All circuit breakers feeding power to the tower must be tied closed with tape, cable, or ties
• E0A08 (C) What does SAR measure? #card
  • A. Signal attenuation ratio
  • B. Signal amplification rating
  • C. The rate at which RF energy is absorbed by the body
  • D. The rate of RF energy reflected from stationary terrain
• E0A09 (C) Which of the following types of equipment are exempt from RF exposure evaluations? #card
  • A. Transceivers with less than 7 watts of RF output
  • B. Antennas that radiate only in the near field
  • C. Hand-held transceivers sold before May 3, 2021
  • D. Dish antennas less than one meter in diameter
• E0A10 (A) When must an RF exposure evaluation be performed on an amateur station operating on 80 meters?
  • A. An evaluation must always be performed
  • B. When the ERP of the station is less than 10 watts
  • C. When the station’s operating mode is CW
  • D. When the output power from the transmitter is less than 100 watts
• E0A11 (D) To what should lanyards be attached while climbing? #card
  • A. Antenna mast
  • B. Guy brackets
  • C. Tower rungs
  • D. Tower legs
• E0A12 (A) Where should a shock-absorbing lanyard be attached to a tower when working above ground? #card
  • A. Above the climber’s head level
  • B. To the belt of the fall-arrest harness
  • C. Even with the climber's waist
  • D. To the next lowes