If a DC circuit has 12 volts and a resistance of 300 ohms, what is the current flowing in the circuit?

To find the current flowing in the circuit, Ohm's Law can be applied, which states that current (I) in a circuit is equal to the voltage (V) divided by the resistance (R). The equation is expressed as:

I = V / R

In this case, the voltage (V) is 12 volts, and the resistance (R) is 300 ohms. Plugging these values into the equation gives:

I = 12 volts / 300 ohms = 0.04 amps, or 40 milliamps.

Hence, the correct answer is that the current flowing in the circuit is 40 milliamps, which accurately reflects the application of Ohm's Law with the provided values. This calculation confirms the relationship between voltage, resistance, and current in a direct current (DC) circuit, illustrating how to derive the current based on the given parameters.