What happens to the total resistance in a parallel circuit when more resistors are added?

In a parallel circuit, the total resistance decreases as more resistors are added. This occurs because parallel resistors provide additional pathways for current flow. Each new resistor added to the circuit offers an alternative route for the electric current, effectively reducing the overall resistance of the circuit.

The formula for calculating total resistance in a parallel circuit can be expressed as:

1/R_total = 1/R_1 + 1/R_2 + 1/R_3 + ...

From this equation, it can be seen that as more resistors are added, the left side of the equation (1/R_total) increases because more terms are being added to the right side. Consequently, since R_total is in the denominator, an increase in the left side leads to a decrease in the total resistance (R_total).

This is fundamentally different from series circuits, where adding more resistors increases the total resistance. In the context of parallel circuits, the ability to accommodate additional resistors results in enhanced current capacity, thereby lowering total resistance. This characteristic is essential for applications such as power distribution systems, where maintaining a lower resistance ensures efficient current flow.