中学实验中,滑动变阻器是用分压式还是用限流式,主要从以下三个方面考虑:一是为使变阻器能正常工作,其额定电流I0必须大于或等于通过干路的最大工作电流Imax;二是满足待测电阻的调压(变流)范围;三是在调压(变流)范围内,使变阻器便于调节,即滑动触头移动时,通过待测电阻两端的电 In the middle school experiment, whether the sliding rheostat uses partial pressure or current limiting is mainly considered in the following three aspects: First, in order for the rheostat to work properly, the rated current I0 must be greater than or equal to the maximum operating current Imax through the trunk. The second is to satisfy the voltage regulation (conversion) range of the resistance to be measured, and the third is to make the rheostat easy to adjust within the range of voltage regulation (current change), that is, when the sliding contact moves, it passes through both ends of the resistance to be measured.