题目内容

减少供电线路损失方法有（）。

A. 应当使电气照明的工作电压保持在允许的电压偏移之内。在采用气体放电光源较多的场所，应采用补偿电容提高功率因数
B. 使用高功率因数的镇流器，以减小线路损失
C. 除为了安全必须采用36V以下照明灯器外，应尽量采用较高电压的照明灯器
D. 照明电源线路应尽量采用三相四线制供电，以减少电压损失。在设计时应尽量使三相照明负荷对称，以免影响灯泡的发光效率

查看答案

搜索结果不匹配？点我反馈

更多问题

Switch R1 has been configured with the root guard feature. What statement is true if the spanning tree enhancement Root Guard is enabled？（）

A. If BPDUs are not received on a non-designated port， the port is moved into the STP loop- inconsistent blocked state
B. IF BPDUs are received on a PortFast enabled port， the port is disabled.
C. If superior BPDUs are received on a designated port， the interface is placed into the root- inconsistent blocked state.
D. If inferior BPDUs are received on a root port， all blocked ports become alternate paths to the root bride.

查看答案