What factor often affects the resistance of shunts?

The factor that often affects the resistance of shunts is high currents. Shunts are precision pieces of equipment utilized to measure electrical currents by providing a low-resistance path through which the majority of the current can flow, allowing for accurate readings. When high currents pass through a shunt, the resistance can change due to effects such as heating, which can alter the electrical characteristics of the shunt material. This change in resistance can lead to inaccuracies in current measurement if not properly accounted for in calibration processes.

Moreover, while other factors such as ambient temperature, electrical resistance, and the type of material used can influence shunt performance, it is the high currents specifically that are known for causing significant changes in resistance through mechanisms like resistive heating. Calibration technicians must be aware of this to ensure precise measurements under different current loads.