What happens to the resistance of a wire as its temperature rises?

• A. It decreases
• B. It remains constant
• C. It increases
• D. It fluctuates

Answer: (C)

As the temperature of a wire increases, the resistance also increases. This phenomenon can be understood through the behavior of the atoms within the conductor. At higher temperatures, the atoms vibrate more vigorously. This increased motion leads to more frequent collisions between the flowing electrons and the vibrating atoms. As a result, the electrons encounter greater opposition as they move through the wire, thereby increasing the resistance.

This relationship between temperature and resistance is particularly evident in metallic conductors, where the resistance is directly proportional to temperature under normal operating conditions. In contrast, some materials may exhibit different behavior where resistance could decrease or remain constant, but for most conductors used in electrical circuits, such as copper or aluminum, the resistance will increase with temperature. This principle is critical in understanding how temperature affects electrical circuits and the importance of managing heat in electrical systems to avoid performance issues or failures.