Lesson 10. Electrical Safety Flashcards
Where should a lightning arrester be installed in a coaxial feed line?
A. At the output connector of a transceiver
B. At the antenna feed point
C. At the ac power service panel
D. On a grounded panel near where feed lines enter the building
D. On a grounded panel near where feed lines enter the building
Which of the following is an important safety rule to remember when using a crank-up tower?
A. This type of tower must never be painted
B. This type of tower must never be grounded
C. This type of tower must not be climbed unless it is retracted, or mechanical safety locking devices have been installed
D. All of these choices are correct
C. This type of tower must not be climbed unless it is retracted, or mechanical safety locking devices have been installed
Which of the following is true when installing grounding conductors used for lightning protection?
A. Use only non-insulated wire
B. Wires must be carefully routed with precise right-angle bends
C. Sharp bends must be avoided
D. Common grounds must be avoided
C. Sharp bends must be avoided
What is the minimum safe distance from a power line to allow when installing an antenna?
A. Add the height of the antenna to the height of the power line and multiply by a factor of 1.5
B. The height of the power line above ground
C. 1/2 wavelength at the operating frequency
D. Enough so that if the antenna falls unexpectedly, no part of it can come closer than 10 feet to the power wires
D. Enough so that if the antenna falls unexpectedly, no part of it can come closer than 10 feet to the power wires
What is the purpose of a safety wire through a turnbuckle used to tension guy lines?
A. Secure the guy line if the turnbuckle breaks
B. Prevent loosening of the turnbuckle from vibration
C. Provide a ground path for lightning strikes
D. Provide an ability to measure for proper tensioning
B. Prevent loosening of the turnbuckle from vibration
What is the purpose of a fuse in an electrical circuit?
A. To prevent power supply ripple from damaging a circuit
B. To remove power in case of overload
C. To limit current to prevent shocks
D. All of these choices are correct
B. To remove power in case of overload
What is a good way to guard against electrical shock at your station?
A. Use three-wire cords and plugs for all AC powered equipment
B. Connect all AC powered station equipment to a common safety ground
C. Install mechanical interlocks in high-voltage circuits
D. All of these choices are correct
D. All of these choices are correct
How does RF radiation differ from ionizing radiation (radioactivity)?
A. RF radiation does not have sufficient energy to cause chemical changes in cells and damage DNA
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
A. RF radiation does not have sufficient energy to cause chemical changes in cells and damage DNA
Which of the following establishes grounding requirements for an amateur radio tower or antenna?
A. FCC Part 97 Rules
B. Local electrical codes
C. FAA tower lighting regulations
D. UL recommended practices
B. Local electrical codes
Why is duty cycle one of the factors used to determine safe RF radiation exposure levels?
A. It affects the average exposure to radiation
B. It affects the peak exposure to radiation
C. It takes into account the antenna feed line loss
D. It takes into account the thermal effects of the final amplifier
A. It affects the average exposure to radiation
Where should a fuse or circuit breaker be installed in a 120V AC power circuit?
A. In series with the hot conductor only
B. In series with the hot and neutral conductors
C. In parallel with the hot conductor only
D. In parallel with the hot and neutral conductors
A. In series with the hot conductor only
Under what circumstances is it safe to climb a tower without a helper or observer?
A. When no electrical work is being performed
B. When no mechanical work is being performed
C. When the work being done is not more than 20 feet above the ground
D. Never
D. Never
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 in the transmitter or antenna system is changed
C. By making sure your antennas have low SWR
D. All of these choices are correct
B. By re-evaluating the station whenever an item in the transmitter or antenna system is changed
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
D. The human body absorbs more RF energy at some frequencies than at others
Who is responsible for ensuring that no person is exposed to RF energy above the FCC exposure limits?
A. The FCC
B. The station licensee
C. Anyone who is near an antenna
D. The local zoning board
B. The station licensee
