At what current load should the rotor or indicator of a meter start to rotate or increment continuously?

The correct answer indicates that the rotor or indicator of a meter should start to rotate or increment continuously at a current load of 0.5 ampere. This load level is typically recognized as the threshold that activates the measurement mechanism within the meter. Below this current, the movement may not be steady, as the energy delivered by the current may be insufficient to create the continual engagement necessary for accurate, consistent measurement.

In practical terms, many measurement devices, especially older or traditional types, are designed with specific sensitivity ranges. A threshold of 0.5 ampere strikes a balance between being low enough to measure smaller loads efficiently while still being high enough to ensure that there is enough energy to produce a reliable and constant reading. This is especially important in electrical applications where precise measurements are crucial for monitoring and managing performance, efficiency, and safety.

Understanding this threshold is a key aspect of working with measurement devices, as it helps technicians and engineers set up and interpret readings accurately in various applications.