Mechanics Practice Exam 2025 – Complete Study Guide for Success

In a parallel circuit, the total resistance decreases as more resistors are added. This occurs because each additional resistor provides an alternative pathway for current to flow. The formula for calculating total resistance (R_total) in a parallel circuit is given by:

1/R_total = 1/R1 + 1/R2 + 1/R3 + ...

In this equation, each resistor contributes to a lower overall resistance than any individual resistor in the circuit. As a result, the total current supplied by the source increases, given that the voltage remains constant. Consequently, the ability of the circuit to conduct electricity improves as more resistors are added, leading to a reduction in total resistance.

Other aspects, such as all resistors sharing equal voltage and current being the same through all resistors, are distinct features of parallel circuits but do not directly address the behavior of total resistance. In a parallel connection, it is essential to recognize that voltage remains constant across each resistor, but the current can vary depending on the resistance of each branch. Thus, the focus here is on how the total resistance is impacted by the configuration of the resistors in a parallel circuit.