第8题: [单项选择]一条35kV线路,长度为25km,线路电抗为0.4Ω/km,最大负荷电流为300A,要求计算线路电抗的标幺值(S=100MV·A)。已知系统最大方式和最小方式下的综合电抗标幺值为0.15和0.2,计算短路电流和电流互感器变比,并计算无时限电流速断保护和过电流保护的定值与灵敏系数。电流互感器的变流比应为()。 A. 300/5 B. 400/5 C. 600/5 D. 800/5 参考答案:B
第18题: [简答题]What is the most common form of non-tariff barriers Explain it in a few words. 参考答案:Quotas or quantitative restrictions are the most common form of non-tariff barriers.
A quota limits the imports or exports of a commodity during a given period of time.