According to Ohm's Law, power is calculated by multiplying the current (I) by the voltage (V). In order to achieve maximum power, the resistance (R) must be at its optimum value. When external resistance is equal to internal resistance, the overall resistance in the circuit is minimized, allowing for maximum current to flow and thus maximizing power output.
No, external resistance cannot be greater than internal resistance for maximum power. This is because a higher external resistance would result in an overall increase in resistance in the circuit, reducing the current flow and therefore decreasing power output.
Changing the external resistance in a circuit affects power output by altering the overall resistance in the circuit. When external resistance is increased, the overall resistance also increases, resulting in a decrease in current flow and therefore a decrease in power output. Similarly, decreasing external resistance will decrease overall resistance and increase power output.
The internal resistance of a power source determines the maximum power that can be delivered to an external load. A lower internal resistance allows for a greater current flow and thus a higher power output. Conversely, a higher internal resistance will limit the current flow and decrease power output.
The equality of external and internal resistance for maximum power applies to simple circuits with a single power source. In more complex circuits, such as those with multiple power sources or non-linear elements, the relationship between external and internal resistance for maximum power may not hold true.