Question

Bulbs A and B in FIGURE Q28.12 are identical, and both are glowing. What happens to each bulb when the switch is closed? Does its brightness increase, stay the same, decrease, or go out? Explain

Short answer

The brightness remains constant.

Step-by-step solution

Given information and formula used 

Given :

Theory used :

The potential difference is equal to the amount of current multiplied by the resistance. A potential difference of one Volt is equal to one Joule of energy being used by one Coulomb of charge when it flows between two points in a circuit.

Determining what happens to each bulb when the switch is closed 

The ground wire has no effect on the circuit's behavior, but it does provide a location on the circuit with zero potential, which is the same as the potential of the earth.

Because the potential difference between the two bulbs and the earth is zero, no current flows to the ground. The current is the same for both bulbs before and after the switch is closed in this situation.

As a result,the brightness remains constant .