Question

In the circuit diagram below, identical bulbs are connected in parallel. Describe and explain the effect on the brightness of the two bulbs if a third identical bulb is also attached in parallel to the two bulbs.

Answer 1

identical bulbs are connected in parallel. Describe and explain the effect on the brightness of the two bulbs if a third identical bulb is also attached in parallel to the two bulbs.

The current in two bulb when resistance is equal is $\frac{I}{2}$

Power$=P=I^{2}R=\frac{I^{2}R}{4}$

when a third resistance is added current becomes $\frac{I}{3}$

The power becomes Power$=P=I^{2}R=\frac{I^{2}R}{9}$

If light bulbs are connected in parallel to a voltage source, the brightness of the individual bulbs remains more-or-less constant as more and more bulbs are added to the “ladder”. The current increases as more bulbs are added to the circuit and the overall resistance decreases.