E0A: Safety: amateur radio safety practices; RF radiation hazards; hazardous materials
What, if any, are the differences between the radiation produced by radioactive materials and the electromagnetic energy radiated by an antenna?
RF radiation does not have sufficient energy to break apart atoms and molecules; radiation from radioactive sources does
There is no significant difference between the two types of radiation
Only radiation produced by radioactivity can injure human beings
Radiation from an antenna will damage unexposed photographic film, ordinary radioactive materials do not cause this problem
When evaluating exposure levels from your station at a neighbor’s home, what must you do?
Make sure signals from your station are less than the uncontrolled MPE limits
Make sure signals from your station are less than the controlled MPE limits
Nothing; you need only evaluate exposure levels on your own property
Advise your neighbors of the results of your tests
Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?
Use a computer-based antenna modeling program to calculate field strength at accessible locations
Use a calibrated antenna analyzer
Use a hand calculator plus Smith-chart equations to calculate the fields
Walk around under the antennas with a neon-lamp probe to find the strongest fields
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?
Each transmitter that produces 5% or more of its maximum permissible exposure limit at accessible locations
Only the most powerful transmitter
Only commercial transmitters
Each transmitter operating with a duty-cycle greater than 50%
What is one of the potential hazards of using microwaves in the amateur radio bands?
The high gain antennas commonly used can result in high exposure levels
Microwaves are ionizing radiation
Microwaves often travel long distances by ionospheric reflection
The extremely high frequency energy can damage the joints of antenna structures
Why are there separate electric (E) and magnetic (H) field MPE limits?
All of these answers are correct
The body reacts to electromagnetic radiation from both the E and H fields
Ground reflections and scattering make the field impedance vary with location
E field and H field radiation intensity peaks can occur at different locations
What is the "far-field" zone of an antenna?
The area where the shape of the antenna pattern is independent of distance
The area of the ionosphere where radiated power is not refracted
The area where radiated power dissipates over a specified time period
The area where radiated field strengths are obstructed by objects of reflection
What does SAR measure?
The rate at which RF energy is absorbed by the body
Synthetic Aperture Ratio of the human body
Signal Amplification Rating
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?
What material found in some electronic components such as high-voltage capacitors and transformers is considered toxic?
Which of these items might be a significant hazard when operating a klystron or cavity magnetron transmitter?
Injury from radiation leaks that exceed the MPE limits
Hearing loss caused by high voltage corona discharge
Blood clotting from the intense magnetic field
Ingestion of ozone gas from the cooling system
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