Amateur Extra Class Exam Question Pool- Subelement E-0
SUBELEMENT E0 – SAFETY - [1 exam question -– 1 group]
E0A - Safety: RF radiation hazards; hazardous materials; grounding
What is the primary function of an external earth connection or ground rod?
A. Reduce received noise
B. Lightning protection
C. Reduce RF current flow between pieces of equipment
D. Reduce RFI to telephones and home entertainment systems
When evaluating RF exposure levels from your station at a neighbor’s home, what must you do?
A. Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
B. Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
C. Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
D. Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits
Over what range of frequencies are the FCC human body RF exposure limits most restrictive?
A. 300 kHz to 3 MHz
B. 3 to 30 MHz
C. 30 to 300 MHz
D. 300 to 3000 MHz
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?
A. Only the most powerful transmitter
B. Only commercial transmitters
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
What is one of the potential hazards of operating in the amateur radio microwave bands?
A. Microwaves are ionizing radiation
B. The high gain antennas commonly used can result in high exposure levels
C. Microwaves often travel long distances by ionospheric reflection
D. The extremely high frequency energy can damage the joints of antenna structures
Why are there separate electric (E) and magnetic (H) field MPE limits?
A. The body reacts to electromagnetic radiation from both the E and H fields
B. Ground reflections and scattering make the field strength vary with location
C. E field and H field radiation intensity peaks can occur at different locations
D. All these choices are correct
How may dangerous levels of carbon monoxide from an emergency generator be detected?
A. By the odor
B. Only with a carbon monoxide detector
C. Any ordinary smoke detector can be used
D. By the yellowish appearance of the gas
What does SAR measure?
A. Synthetic Aperture Ratio of the human body
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
Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?
B. Zinc oxide
C. Beryllium Oxide
D. Uranium Hexafluoride
What toxic material may be present in some electronic components such as high voltage capacitors and transformers?
A. Polychlorinated biphenyls
D. Polymorphic silicon
Which of the following injuries can result from using high-power UHF or microwave transmitters?
A. Hearing loss caused by high voltage corona discharge
B. Blood clotting from the intense magnetic field
C. Localized heating of the body from RF exposure in excess of the MPE limits
D. Ingestion of ozone gas from the cooling system