Electrical and RF Safety Flashcards
7 cards from real Ham Radio General Class Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical and RF Safety flashcards as text
What is the primary hazard of working near high-voltage capacitors even after power is removed?
Answer: They can retain a lethal charge for extended periods
High-voltage capacitors can store a lethal charge long after power is removed, so they must be safely discharged before any work is performed.
Which body path for current flow is considered most dangerous?
Answer: Hand to hand
Hand-to-hand current flow is most dangerous because it passes directly through the chest and heart, which can cause cardiac arrest.
What does the term 'Maximum Permissible Exposure' (MPE) refer to in RF safety?
Answer: The maximum RF field strength that humans can be safely exposed to
MPE refers to the maximum level of RF electromagnetic field exposure that is considered safe for humans, as defined by FCC regulations.
What is the safest way to discharge a high-voltage capacitor before handling?
Answer: Use a resistor in series with an insulated probe to bleed the charge slowly
Using a resistor in series with an insulated probe bleeds the capacitor charge slowly and safely without creating a damaging current spike.
Why is RF exposure more of a concern at higher power levels in the HF/VHF range?
Answer: Biological tissue absorbs more RF energy at certain frequencies
Biological tissue absorbs RF energy at rates that vary with frequency, and at HF/VHF ranges and high power, this absorption can cause significant tissue heating.
What is a key reason amateur radio operators must perform an RF exposure evaluation?
Answer: To comply with FCC regulations protecting operators and the public from RF overexposure
FCC regulations require amateurs to evaluate their stations to ensure RF exposure to people remains within safe MPE limits.
Which type of antenna installation generally minimizes RF exposure to people in a residential setting?
Answer: An antenna mounted high above the roofline on a tower
Mounting an antenna high on a tower keeps it far away from people, reducing RF exposure by increasing the distance between the antenna and inhabited areas.