Light bulbs are considered resistor in parallel circuit. Adding more light bulbs to a parallel circuit will have an unexpected result by having less overall resistance while adding resistor in an unrelated branch will provide another pathway to direct charge to the main area of resistance inside the circuit.
Explanation:
The net resistance in the parallel combination of the circuit is less in comparison to the net the resistance in the series combination of the circuit.
In the series combination of the bulbs when the bulbs are added then the net resistance of the combination increases. Then, brightness of the bulbs decreases as the current decreases.
If the light bulbs are connected in parallel to the voltage source, the brightness of each bulbs less or more constant.
If more light bulbs are added in the parallel combination then the current increases as the net resistance decreases. The brightness of the light bulbs increases.
