Chapter 35, Problem 43A

A battery has internal resistance, so if the current it supplies goes up, the voltage it supplies goes down. If too many bulbs are connected in parallel across a battery, will their brightness diminish? Explain.

To determine

Whether the brightness of bulbs diminishes or not.

Explanation of Solution

Introduction:

The internal resistance opposes the flow of current in the circuit and it produces heat in the device.

The internal resistance opposes the flow of current. If the supply current increase, then the voltage across the device goes down due to the generation of heat due to internal resistance.

If too many bulbs are connected in parallel across the battery, then the voltage across each bulb remains the same and the current varies with resistance. The current in each bulb diminishes due to internal resistance.

Conclusion:

The brightness of the bulb diminishes due to the reduction in the current because of the internal resistance.