Chapter 23, Problem 82A

To determine

To explain: The effect of failure of one lamp on the current through the other two lamps in a three-lamp series circuit.

Answer to Problem 82A

The current in the other two lamps becomes zero.

Explanation of Solution

Given:

A series circuit consisting of three lamps and one lamp burns out.

Consider the series circuit of three lamps as shown in Figure 1

  

Figure 1

In a series circuit, the same current flows through all the lamps. When one of the lamps, say L₃ burns out, the it creates an open path in the circuit, and hence, the current flow is not possible. Thus, the current flow through the other two lamps becomes zero.

Conclusion:

The current flow through the other two lamps in the series circuit becomes zero if one lamp burns out.