What happens when a circuit is short-circuited?

When a circuit is short-circuited, the current bypasses the load, causing a sudden increase in current flow.

A short circuit is a situation where a low-resistance pathway, often an unintended one, forms between two points in an electrical circuit. This new pathway allows the electric current to bypass the intended route, which usually includes a load such as a light bulb or a resistor. The result is a sudden surge in current flow, which can be potentially dangerous.

The reason for the sudden increase in current is due to Ohm's law, which states that the current through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them. In a short circuit, the resistance is extremely low, almost zero, which means the current will be extremely high.

This sudden surge in current can cause a number of problems. Firstly, it can generate a lot of heat. If the circuit's components, such as wires and switches, are not designed to handle this level of current, they can overheat, melt, or even catch fire. Secondly, it can damage electronic components. Many electronic devices are designed to work with a specific current level, and a sudden surge can cause them to fail.

To protect against short circuits, many electrical systems include safety devices such as fuses and circuit breakers. A fuse contains a small piece of wire that melts and breaks the circuit if the current gets too high. A circuit breaker is a switch that automatically turns off if it detects a short circuit. These devices are designed to prevent damage and reduce the risk of fire.

In conclusion, a short circuit is a potentially dangerous situation that can cause damage and fire. It's important to understand how they occur and how to prevent them.