What characteristic is shown by a circuit if its current exceeds its rated capacity?

When the current in a circuit exceeds its rated capacity, the most significant characteristic that arises is overheating. This occurs because the increased current flow generates more heat than the circuit components are designed to dissipate. As components heat up, they can become damaged or compromised, leading to potential failure.

In electrical systems, every component, including wires, connectors, and electronic devices, has a specific current rating that indicates the maximum safe current they can handle. When this limit is surpassed, it leads to resistance within the circuit generating excess heat, causing components to risk burnout or even fire hazards in extreme cases.

The other options, such as short-circuit, underloading, and normal operation, do not pertain to a circuit exceeding its current rating in the same way. A short-circuit specifically refers to an unintended low-resistance connection that allows excessive current to flow, but it is a different situation than simply exceeding a rated capacity. Underloading indicates that a circuit is not fully utilized, which does not apply when discussing the effects of exceeding current ratings. Normal operation refers to a circuit functioning within its rated parameters without any issues.