A change in total resistance in parallel circuits affects what aspect of the circuit?

In parallel circuits, the total resistance changes when additional resistors are added or removed. This variation in total resistance directly influences the distribution of current throughout the circuit.

According to Ohm's Law, which states that current is equal to voltage divided by resistance (I = V/R), if the total resistance decreases, the overall current supplied by the voltage source will increase. Conversely, if the total resistance increases, the overall current will decrease.

In parallel circuits, the voltage across each component remains constant, as all components share the same voltage from the source. Therefore, while the current changes with variations in total resistance, the voltage does not. This distinction clarifies why the correct answer focuses on the effect of total resistance changes solely on current rather than on both voltage and current.