In the circuit given below, identify the lamp (L1, L2, L3 or L4) whose failure would not interrupt the power supply to the other lamps.
Show Hint
In a combined series-parallel circuit, the failure of a component in a parallel branch only affects that branch. The failure of a component in the main series part affects the entire circuit.
Step 1: Understanding the Concept:
In a circuit, components in series share the same current path. If one fails, the circuit breaks. Components in parallel have independent current paths. Step 2: Detailed Explanation:
Looking at the diagram:
\( L_1 \) is in series with the entire combination. If it fails, the whole circuit opens.
\( L_2, L_3, \) and \( L_4 \) are in parallel branches.
If \( L_4 \) fails, the branch containing \( L_4 \) becomes an open circuit. However, current can still flow from the battery through \( L_1 \) and then through the other parallel branches (\( L_2 \) and \( L_3 \)).
Thus, \( L_4 \) (as a parallel component) does not stop the flow to others. Step 3: Final Answer:
The correct lamp is \( L_4 \).
