What is the resistance found in good, usually closed relay contacts?

The resistance found in good, usually closed relay contacts is considered to be approximately 0 ohms. In practical terms, this means that the contacts are effectively short-circuited when closed, allowing electricity to pass through without significant resistance or energy loss. This "0 ohms" concept represents an ideal condition where the contacts provide the least possible resistance, ensuring efficient operation of the electrical circuit they control.

Relay contacts are designed to minimize resistance for a number of reasons, including reducing heat generation, maintaining voltage levels, and ensuring reliability. While in reality, there may be minuscule resistance values due to factors like contact material and surface condition, they are close enough to zero that they can be considered as such in a functional context.

In contrast, other answers suggest non-zero resistance values that would indicate that the relay contacts are either not functioning optimally or are showing wear or failure, which would not be expected in a properly functioning relay. Therefore, understanding that good relay contacts have a resistance close to zero is crucial for troubleshooting and ensuring proper circuit performance.