What is the correct equation for total resistance in a parallel circuit?

In a parallel circuit, the total resistance is found using the reciprocal of the individual resistances. The correct equation is that the reciprocal of the total resistance equals the sum of the reciprocals of each resistance. This relationship reflects the fact that multiple pathways for current exist in parallel configurations, allowing the total current to increase as each additional resistor is added.

This equation, 1/R_total = 1/R1 + 1/R2 + 1/R3, explains that as more resistors are added in parallel, the total resistance decreases. Each resistor provides an alternative path for current, thereby reducing the overall resistance in the circuit.

Understanding this equation is crucial for analyzing parallel circuits, as it can significantly impact the behavior of electrical systems, influencing factors like current flow and voltage distribution. The other options do not correctly represent the principles governing parallel circuits, which is why they do not provide the right formulation for calculating total resistance in such setups.