第20题: [多项选择]如上下级断路器间连接导体阻抗小,上下级断路器出线端处预期短路电流数值判别很小,则可将上级断路器选为带短延时脱扣器,整定上级断路器短延时动作电流为下级断路器动作电流值的( )。 A. 1.1~1.15倍 B. 1.2~1.25倍 C. 1.25~1.35倍 D. 1.1~1.35倍 参考答案:B 答案解析:[解析] 《钢铁企业电力设计手册》或《复习指导书(供配电)》9.2.7.8。
第21题: [单项选择]The distance between any two meridians measured along a parallel of latitude (). A. increases in north latitude and decreases in south latitude B. decreases as DLO increases C. increases with increased latitude D. decreases with increased latitude 参考答案:D