Sub Element GO: Electrical and RF Safety Flashcards
What is one way that RF energy can affect human body tissue?
It heats body tissue
Which of the following properties is important in estimating whether an RF signal exceeds the maximum permissible exposure (MPE)?
Its duty cycle
Its frequency
Its power density
All these choices are correct
How can you determine that your station complies with FCC RF exposure regulations?
By calculation based on FCC OET Bulletin 65
By calculation based on computer modeling
By measurement of field strength using calibrated equipment
All these choices are correct
What does “time averaging” mean in reference to RF radiation exposure?
The total RF exposure averaged over a certain time
What must you do if an evaluation of your station shows RF energy radiated from your station exceeds permissible limits?
Take action to prevent human exposure to the excessive RF fields
What precaution should be taken when installing a ground-mounted antenna?
It should be installed such that it is protected against unauthorized access
What effect does transmitter duty cycle have when evaluating RF exposure?
A lower transmitter duty cycle permits greater short-term exposure levels
Which of the following steps must an amateur operator take to ensure compliance with RF safety regulations when transmitter power exceeds levels specified in FCC Part 97.13?
Perform a routine RF exposure evaluation
What type of instrument can be used to accurately measure an RF field?
A calibrated field strength meter with a calibrated antenna
What is one thing that can be done if evaluation shows that a neighbor might receive more than the allowable limit of RF exposure from the main lobe of a directional antenna?
Take precautions to ensure that the antenna cannot be pointed in their direction
What precaution should you take if you install an indoor transmitting antenna?
Make sure that MPE limits are not exceeded in occupied areas
Which wire or wires in a four-conductor connection should be attached to fuses or circuit breakers in a device operated from a 240 VAC single phase source?
Only the two wires carrying voltage
According the National Electrical Code, what is the minimum wire size that may be used safely for wiring with a 20 ampere circuit breaker?
AWG number 12
Which size of fuse or circuit breaker would be appropriate to use with a circuit that uses AWG number 14 wiring?
15 amperes
Which of the following is a primary reason for not placing a gasoline-fueled generator inside an occupied area?
Danger of carbon monoxide poisoning
Which of the following conditions will cause a Ground Fault Circuit Interrupter (GFCI) to disconnect the 120 or 240 Volt AC line power to a device?
Current flowing from one or more of the voltage-carrying wires directly to ground
Which of the following is covered by the National Electrical Code?
Electrical safety inside the ham shack
Which of these choices should be observed when climbing a tower using a safety belt or harness?
Confirm that the belt is rated for the weight of the climber and that it is within its allowable service life
What should be done by any person preparing to climb a tower that supports electrically powered devices?
Make sure all circuits that supply power to the tower are locked out and tagged
Which of the following is true of an emergency generator installation?
The generator should be located in a well-ventilated area
Which of the following is a danger from lead-tin solder?
Lead can contaminate food if hands are not washed carefully after handling the solder
Which of the following is good practice for lightning protection grounds?
They must be bonded together with all other grounds
What is the purpose of a power supply interlock?
To ensure that dangerous voltages are removed if the cabinet is opened
What must you do when powering your house from an emergency generator?
Disconnect the incoming utility power feed
What precaution should you take whenever you adjust or repair an antenna?
Turn off the transmitter and disconnect the feed line
