Which description best defines a short circuit?

Which description best defines a short circuit?

• A. A device that stores electrical energy
• B. A path of no load or where the load was bypassed
• C. An open switch in series with load
• D. A circuit that reduces current to zero

Answer: (B)

A short circuit happens when a path with very low resistance forms that bypasses the intended load, so current flow takes the easy route around the device instead of through it. The description of a path with no load or where the load has been bypassed fits this idea: the circuit provides a low-impedance shortcut, causing a large amount of current to flow and the load to receive little or no current at all. This is exactly what a fault condition in a circuit does, which is why protective devices like fuses or breakers are designed to respond to it and why wires can overheat if not protected. The other descriptions describe different situations. A device that stores energy is something like a capacitor or battery, not a short. An open switch in series with the load blocks current entirely, which is an open circuit. A circuit that reduces current to zero is also an open or current-limiting condition, not a short.

A short circuit happens when a path with very low resistance forms that bypasses the intended load, so current flow takes the easy route around the device instead of through it. The description of a path with no load or where the load has been bypassed fits this idea: the circuit provides a low-impedance shortcut, causing a large amount of current to flow and the load to receive little or no current at all. This is exactly what a fault condition in a circuit does, which is why protective devices like fuses or breakers are designed to respond to it and why wires can overheat if not protected.

The other descriptions describe different situations. A device that stores energy is something like a capacitor or battery, not a short. An open switch in series with the load blocks current entirely, which is an open circuit. A circuit that reduces current to zero is also an open or current-limiting condition, not a short.