Final answer:
The maximum power that can be delivered to a resistive load by a circuit occurs when the resistance of the load is equal to the internal resistance of the battery or source.
Step-by-step explanation:
The maximum power that can be delivered to a resistive load by a circuit can be found using the formula P = I²R, where P is the power, I is the current flowing through the load, and R is the resistance of the load.
According to Ohm's law, V = IR, where V is the voltage across the load. By substituting this into the power formula, we get P = (V/R)².
To maximize the power delivered to the load, the resistance of the load should be equal to the internal resistance of the battery or the source. This is because maximum power transfer occurs when the load resistance is matched to the source resistance.