In the circuit given below, identify the lamp (L 1 , L 2 , L 3 and L 4 ) whose failure would not interrupt the power supply to the other lamps.

L₂

Reason — In the circuit, L₁ and L₃ are placed in the main vertical branch, so if either of them fails, the circuit path breaks and current cannot reach the other lamps.

L₄ is also part of the lower main path; its failure would interrupt the current in that branch.

However, L₂ is connected in a separate parallel branch between the two sides of the circuit so if L₂ fails, only that branch becomes open while current can still flow through the rest of the circuit containing L₁, L₃, and L₄.

Therefore, the failure of L₂ would not interrupt the power supply to the other lamps.