What method is used to find the equivalent resistance of two resistors in parallel?

The product over sum method is the correct approach for finding the equivalent resistance of two resistors in parallel. When resistors are placed in parallel, the total or equivalent resistance can be calculated using the formula:

[

R_{eq} = \frac{R_1 \cdot R_2}{R_1 + R_2}

]

This formula effectively combines the two resistances to determine how they share the total current while maintaining the relationship to the voltage across them. This method highlights how parallel resistors decrease the total resistance in the circuit since they offer multiple paths for current to flow.

While the other methods might apply in different contexts, they do not correctly calculate the equivalent resistance for parallel resistors. The sum of resistances is relevant for resistors in series, where the total resistance is simply the arithmetic sum of each resistor's value. The series resistance method exclusively applies to series configurations, as does the reciprocal method, which may lead to confusion unless properly applied. In the context of two resistors in parallel specifically, the product over sum method correctly provides the equivalent resistance, clearly illustrating how their interaction influences the overall resistance of the circuit.