What values are needed to determine the maximum available output wattage of a power supply?

To determine the maximum available output wattage of a power supply, the correct approach involves using output voltage and output amperage. Wattage is calculated using the formula:

Wattage (Watts) = Voltage (Volts) × Amperage (Amps)

This means that by knowing the output voltage (the potential difference) and the output amperage (the current supplied), you can directly calculate the total power output of the power supply.

In this context, input voltage and input amperage relate to how the power supply draws power from the mains or other sources but do not directly help in calculating the output wattage that the device can deliver. Using only voltage and resistance does not provide sufficient information to determine wattage because it lacks the necessary component of current (amperage), which is essential to complete the power calculation.

Therefore, the relationship between output voltage and output amperage is critical for finding the maximum output wattage, making it the right choice.