有线电视系统的系统载波互调比(IM)的最小设计值为()。...
Saturday, September 17, 2022
长时间工作或停留的房间或场所,选用照明光源的显色指数不宜小于()...
Friday, September 16, 2022
如要将一个最大幅度为5.1V的模拟信号转换为数字信号,要求输入每...
Friday, September 16, 2022
Saturday, June 3, 2023
绝缘配电线路与甲类火灾危险性的生产厂房、甲类物品库房、易燃、易爆...
Friday, September 16, 2022
Friday, September 16, 2022
环形接地体和内部环形导体应连到钢筋或金属立面等其他屏蔽构件上,宜每隔()连接一次。A、15mB、10mC、5mD、3m...
Wednesday, October 26, 2022
某110kV户外变电所,设有两台主变压器,2回电源进线(电源来自...
Saturday, September 17, 2022
一声波波源相对媒质不动,发出的声波频率是V0。设以观察者的运动速...
Friday, September 16, 2022
Sunday, September 11, 2022
速度调节器采用电路运算放大器,它具有两个输入端,同相输入端和()...
Saturday, September 17, 2022
某300MW火力发电厂,厂用电引自发电机,厂用变主变为Dynll...
Friday, September 16, 2022
局部放电试验使用脉冲电流法时,可以有直接法和平衡法。()...
Friday, September 16, 2022
Friday, September 16, 2022
Saturday, September 17, 2022
Saturday, September 17, 2022
根据《低压配电设计规范》,直敷布线可用于正常环境的屋内场所,并应...
Friday, September 16, 2022
Friday, September 16, 2022
金属加热到一定温度会由固态熔化成液态,开始转化的温度称为( )。...
Saturday, September 17, 2022
可编程序控制器的输入/输出(I/O)模块,是CPU与现场I/O设...
Thursday, September 15, 2022