What is the current required to deliver 120 watts at a voltage of 12 volts DC?

• A. 8 amperes
• B. 10 amperes
• C. 12 amperes
• D. 14 amperes

Answer: (B)

To determine the current required to deliver a specific amount of power at a given voltage, you can use the formula derived from Ohm's Law and the power formula:

Power (P) = Voltage (V) × Current (I).

In this case, you need to find the current (I) when the power (P) is 120 watts and the voltage (V) is 12 volts DC. Rearranging the formula gives:

Current (I) = Power (P) / Voltage (V).

Substituting the known values into the formula results in:

I = 120 watts / 12 volts = 10 amperes.

This calculation shows that to deliver 120 watts at 12 volts, a current of 10 amperes is required. This fundamental relationship between power, voltage, and current is crucial for understanding electrical systems and ensuring safe and efficient operation of devices and circuits in ham radio and other applications.