What happens to the brightness of each bulb when you add another parallel branch circuit of 60W bulbs?

When additional parallel branches of 60W bulbs are added to a circuit, the brightness of each individual bulb remains the same as it was before the new branches were added. In a parallel circuit, each bulb experiences the same voltage from the power source. This means that the electrical energy supplied to each bulb does not change with the addition of more bulbs.

As more branches are added, they provide additional paths for current to flow, effectively decreasing the overall resistance of the circuit. However, since the voltage across each parallel branch remains constant, the wattage (power) consumed by each bulb does not change, resulting in consistent brightness for each light bulb.

This key characteristic of parallel circuits ensures that each bulb operates independently of the others, preserving their brightness despite the presence of additional bulbs in the circuit.