Chapter 23, Problem 88A

a.

To determine

The brighter lamp in a parallel circuit.

Explanation of Solution

Introduction:

In a parallel circuit there is the same voltage across the loads.

As the voltage is the same across the loads, the power is inversely related to the resistance of the bulbs. Hence, the bulb with lower resistance will be brighter than the bulb with higher resistance.

Conclusion:

In parallel, the bulb with lower resistance will be brighter or uses more power.

b.

To determine

The brighter lamp in a series circuit.

Explanation of Solution

Introduction:

In a series circuit, there is voltage drop across each load according to the resistance offered.

In a series circuit, same current moves through the loads. Therefore, there is a greater voltage drop across the load with more resistance which glows brighter.

Conclusion:

In a series circuit the bulb with higher resistance glows brighter.