Ham Radio General Class Practice Test

What is the minimum wire size that may be safely used for a circuit that draws up to 20 amperes of continuous current?

1. AWG number 20

2. AWG number 16

3. AWG number 12

4. AWG number 8

The correct answer is: AWG number 12

The minimum wire size that may be safely used for a circuit drawing up to 20 amperes of continuous current is AWG number 12. This wire gauge is commonly recommended because it can adequately handle the current without excessive voltage drop or overheating over longer distances. The American Wire Gauge (AWG) system provides a standardized method for specifying wire sizes, where a lower gauge number indicates a thicker wire capable of carrying more current. For a circuit that draws 20 amperes, it is crucial to consider both the continuous current rating and the wire's ability to dissipate heat effectively. AWG number 12 has a safe continuous current capacity of approximately 20 amperes, making it suitable for general household wiring and similar applications. Sizing up ensures safety and efficiency, as using a wire gauge that is too small for the current can lead to overheating and potentially create a fire hazard. Other wire gauges listed in the options, like AWG numbers 20 and 16, are not adequate for sustained use at 20 amperes, as they would exceed their current-carrying capacity and risk overheating. AWG number 8, while capable of handling much more current, is unnecessarily thick for this specific application and would be more than what is required