Physics
Answer

option 4
Reason — In circuit 4, the key is closed, completing the circuit. In the other circuits the key (K) is left open, so the circuits are incomplete. For an electric circuit to function, every component must conduct current. If the circuit is broken at any point, the circuit remains open and no current flows.
Related Questions
The presence of …………… in the path makes a circuit incomplete and current does not flow.
- conductor
- ammeter
- voltmeter
- insulator
Connecting wires are made of substances that have :
- highly conducting material
- negligible resistance
- free electrons in a large number
- all of these
Name one d.c. source and one a.c. source.
What is an electric cell?


