Final answer:
The percentage of a battery's emf reaching a load resistor depends on the battery's internal resistance and the load resistance. As the internal resistance increases relative to the load resistance, the current, and consequently the voltage across the load resistor, decreases.
Step-by-step explanation:
The question seeks to understand what percentage of a battery's electromotive force (emf) is actually reaching the load resistor (R) in a circuit. To find this, one would consider the emf, the internal resistance (r), and the load resistance (R), using the formula Vterminal = emf - Ir, where Vterminal is the voltage across the load resistor and I is the current in the circuit.
When the internal resistance of the battery is equal to the load resistance (R = r) and then the internal resistance triples, the current through the load resistor is affected. It can be calculated using Ohm's Law, by the relationship I = emf / (r + R), which demonstrates that the current is inversely proportional to the total resistance in the circuit. As internal resistance increases, the current decreases, thereby reducing the voltage across the load resistor and limiting the power it receives.
Performing a graphical analysis using the provided data to determine the emf and internal resistance of a battery involves plotting the terminal voltage against the current and extrapolating to the point where the terminal voltage would equal the emf (I = 0). The internal resistance can be found from the slope of this graph.