Ham Radio General Class Practice Test

What safety feature does a power-supply bleeder resistor provide?

1. It acts as a fuse for excess voltage

2. It discharges the filter capacitors

3. It removes shock hazards from the induction coils

4. It eliminates ground-loop current

The correct answer is: It discharges the filter capacitors

A bleeder resistor serves an important safety function by discharging filter capacitors in a power supply. After a power supply is turned off, the filter capacitors can retain a dangerous amount of voltage, which poses a shock hazard if the capacitors are not discharged. The bleeder resistor connects across the capacitor and allows it to gradually discharge its stored energy safely over time. This is crucial for preventing potential electric shock when someone works on the circuitry, ensuring that the capacitors are at a safe voltage before any maintenance is performed. In contrast, while other options may pertain to different electrical safety considerations or function, they do not describe the role of the bleeder resistor specifically. For instance, a fuse protects against excess current but does not discharge capacitors. Induction coils relate to electromagnetic fields, while ground-loop issues deal with currents caused by multiple grounding points, neither of which is relevant to the function of a bleeder resistor.