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直导线在磁场中运动一定会产生感应电动势
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负载电功率为正值表示负载吸收电能,此时电流与电压降的实际方向一致
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在接通和断开电容器组时,要选用不能产生危险过电压的断路器,并且断路器的额定电流不应低于1.3倍电容器组的额定电流
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对于电路中的任一回路,沿任一方向绕行一周,各电源电动势的代数和等于各电阻电压降的代数和
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动力和照明配电箱的内部结构现已向积木式和抽屉式发展
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进行绝缘修补时首先要清洁损伤处的污秽,然后可用绝缘自粘带缠饶修补,缠绕时要注意防尘埃和防水分
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测量电容器绝缘电阻后,先停止摇动,然后取下测量引线
【判断题】
电阻两端的交流电压与流过电阻的电流相位相同,在电阻一定时,电流与电压成正比
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两部制电价计费的用户,其固定电费部分不实行《功率因数调整电费办法》
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低压断路器的机构由传动机构和操动机构两部分组成
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高压隔离开关是一种没有专门灭弧装置的开关设备,所以不允许切断负荷电流或短路电流
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高压验电器无需定期进行试验,可使用没有试验过的或超过试验周期的验电器验电
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在电磁感应中,感应电流和感应电动势是同时存在的;没有感应电流,也就没有感应电动势
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剥除电缆的每一道工序都必须保证不损伤内层需要保留的部分
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使用高压验电器验电时,应选用与被测设备额定电压相应电压等级的专用验电器,并戴绝缘手套操作
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磁通是表示穿过单位截面的磁力线数量的物理量
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低压混凝土杆一般做成拔梢型,梢径一般为150mm或230mm
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3×1.5(6)A、3×100V三相三线有功电能表,经200/5电流互感器和10000/100电压互感器计量,倍率为4000
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三相三线两元件电能表抽去中相电压时应几乎停走
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塑壳式自动空气断路器可以手动操作也可以自动操作
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对远程自动抄表异常客户现场核抄时,如现场抄见读数与远程获取读数不一致,以远程获取读数为准
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对于一台轻负载电动机,其熔体的额定电流可等于2.5倍电动机额定电流
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电流互感器二次侧不允许开路,对二次侧双绕组互感器只用一个二次回路时,另一个绕组应可靠连接
【判断题】
在低压配电系统中,三相对称电源接成三相四线制,可向负载提供线电压380V,相电压为220V两种电压
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当变压器储油柜或防爆管发生喷油时,应立即停止运行
【判断题】
单位时间内流过导体横截面的电荷量叫做电流强度
【判断题】
绝缘导线连接前,应先剥去导线端部的绝缘层,并将裸露的导体表面清擦干净
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如果三相正弦量频率相同、幅值相等、彼此间相位差为0°,即三者同相,则称它们为负序对称三相正弦量
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10kV电力客户需要新装或增容申请时,应携带营业执照或组织机构代码证
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隔离开关动、静触头的接触压力是靠两端接触弹簧维持的
【判断题】
连接户外隔离开关的上、下引线要压紧,与线路导线的连接要紧密可靠
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一段电路的电压UAB=-10V,该电压实际上是A点电位高于B点电位
【判断题】
三角形接法的三相异步电动机若误接成星形,当负荷转矩不变时,则电动机转速将会比三角形接法时稍有增加或基本不变
【判断题】
因接地装置本身电阻较大,一般不可忽略不计
【判断题】
熔体规格应根据电路中上下级之间保护定值的配合要求来选择,以免发生越级熔断
【判断题】
桩和锚都是线路施工中承载拉力的起重工具
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