What is a short circuit?

• A. Unintended contact causing excessive current flow
• B. A circuit with no power
• C. A high-resistance path
• D. A circuit with a blown fuse intentionally

Answer: (A)

A short circuit happens when a low-resistance path forms that lets current bypass the intended load, causing a surge of current. In normal operation, electricity flows through the device or circuit element it’s meant to power; but when a direct connection occurs—such as damaged insulation letting a wire touch metal or two conductors touch each other—the current finds the easiest path and flows with little resistance. That heavy current can overheat wires, blow fuses, damage components, or even start a fire.

This isn’t the same as a circuit with no power, where the current can’t complete a path at all (an open circuit). It’s also not a high-resistance path, which would restrict current rather than surge it. And it isn’t a circuit with a fuse blown on purpose—the fuse is simply interrupting current to protect the system, not creating a short.