What happens to total resistance when an additional light is added in parallel to two existing lights?

When an additional light is added in parallel to two existing lights, the total resistance of the circuit decreases. This is because in a parallel circuit, the total resistance can be calculated using the formula:

[ \frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} ]

Here, each (R) represents the resistance of each of the lights. When you add another light, you are essentially adding another pathway for current to flow. This additional pathway reduces the overall resistance because more routes are available for the electric current, allowing it to flow more freely.

As a result, the total current drawn from the power source increases, while the voltage remains constant. The higher current capacity is due to the lower resistance, which is a key characteristic of parallel circuits. Hence, when another light is added in parallel, total resistance decreases, confirming that the correct answer is that the total resistance will decrease.