Recreational Vehicle (RV) Technician Practice Test

What must be calculated to determine the correct wire size for a circuit?

1. Voltage

2. Amperage

3. Resistance

4. Power

The correct answer is: Amperage

To determine the correct wire size for a circuit, amperage must be calculated. Amperage, or the amount of electric current flowing through the wire, is crucial because it directly relates to the wire's ability to safely carry current without overheating. Each wire has a specific capacity, known as its ampacity, which indicates how much current it can handle safely. If the amperage exceeds the wire's capacity, it could lead to excessive heat build-up and potentially cause a fire hazard. While voltage, resistance, and power are important electrical parameters, they do not directly determine wire size. Voltage pertains to the potential difference driving the current, resistance refers to the opposition to current flow, and power is the product of current and voltage. However, none of these concepts replace the need to calculate the amperage to ensure the selected wire can handle the expected current load within the circuit safely.