If one component fails in a series circuit, what happens to the circuit?

If one component fails in a series circuit, what happens to the circuit?

• A. The circuit remains intact
• B. The entire circuit stops
• C. The current doubles in others
• D. Voltage across others increases

Answer: (B)

In a series circuit, the same current must flow through every component along a single path. If one component fails by opening (stops conducting), the path is broken and no current can continue around the loop. That stops the entire circuit, so all devices in that loop stop getting current. The idea that current would double in the other parts or that the voltage across the remaining components would rise doesn’t happen when the circuit is opened, because there is no current to create voltage drops. (Note: if a failure were a short instead of an open, the behavior would be different, but the usual interpretation of a component failing in series is an open that halts the circuit.)

In a series circuit, the same current must flow through every component along a single path. If one component fails by opening (stops conducting), the path is broken and no current can continue around the loop. That stops the entire circuit, so all devices in that loop stop getting current. The idea that current would double in the other parts or that the voltage across the remaining components would rise doesn’t happen when the circuit is opened, because there is no current to create voltage drops. (Note: if a failure were a short instead of an open, the behavior would be different, but the usual interpretation of a component failing in series is an open that halts the circuit.)