Total Resistance and Current in Parallel Circuits

What happens to the total resistance and total current as more devices are added to a parallel circuit?

Choose the correct answer:

A. RT increases and IT decreases.

B. RT decreases and IT increases.

C. RT increases and IT increases.

D. RT decreases and IT decreases.

Answer:

As more devices are added to a parallel circuit, the total resistance (RT) decreases because there are more paths available for the current to flow through, reducing the overall resistance in the circuit.

However, the total current (IT) increases as more devices are added to a parallel circuit because the voltage across each device remains the same, and as the total resistance decreases, Ohm's Law dictates that the total current must increase to maintain the same voltage across the circuit.

When devices are added to a parallel circuit, the total resistance decreases because each device creates additional paths for current flow. As a result, the overall resistance in the circuit diminishes, allowing current to flow more easily.

On the other hand, the total current increases in a parallel circuit with the addition of more devices. This is due to the fact that the voltage across each device remains constant, and with the total resistance decreasing, the total current must increase to uphold the voltage throughout the circuit according to Ohm's Law.

Therefore, the relationship between total resistance and total current in a parallel circuit is such that as more devices are added, the total resistance decreases while the total current increases.