【单选题】
交流电在单位时间（1s）完成 变化的次数，叫做频率。
A. 频率性
B. 周期性
C. 时间性
D. 集结性
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相关试题
【单选题】
交流电在单位时间（1s）完成周期性变化的次数，叫做 。
A. 赫兹
B. 相位差
C. 角频率
D. 频率
【单选题】
是变压器的组成部分。
A. 绕组
B. 定子
C. 转子
D. 高压电线
【单选题】
变压器是按 原理工作的。
A. 右手定则
B. 左手定则
C. 欧姆定律
D. 电磁感应
【单选题】
是按电磁感应原理工作的。
A. 辅助电源
B. 避雷器
C. 变压器
D. 变流器
【单选题】
变压器在铁芯中产生 。
A. 感应电动势
B. 感应电流
C. 感应电压
D. 交变磁通
【单选题】
在原、副线圈产生感应电动势。
A. 变流器
B. 辅助电源
C. 变压器
D. 电动机
【单选题】
直流电机由静止的 和旋转的转子两大部分组成。
【单选题】
直流电机由静止的定子和旋转的 两大部分组成。
【单选题】
直流电机在 和转子之间有一定大小的间隙(称气隙)。
【单选题】
直流电机具有 。
A. 逆变性
B. 黏着性
C. 可逆性
D. 回转性
【单选题】
具有可逆性。
A. 主断路器
B. 受电弓
C. 充电机
D. 直流电机
【单选题】
直流电机的 ，指的是一台直流电机既可作发电机运行，也可作电动机运行。
A. 逆变性
B. 方向性
C. 可逆性
D. 回转性
【单选题】
最基本的作用是单向导通。
A. 二极管
B. 三极管
C. PN结
D. IGBT元件
【单选题】
二极管最基本的作用是 。
A. 放大信号
B. 整流
C. 逆变
D. 单向导通
【单选题】
的作用是把微弱信号放大成幅值较大的电信号。
A. 二极管
B. 三极管
C. 集电极
D. PN结
【单选题】
三极管的作用是把微弱信号放大成 较大的电信号。
A. 初相位
B. 角频率
C. 频率
D. 幅值
【单选题】
：大小和方向随时间连续变化。
A. 离散信号
B. 脉冲信号
C. 放大信号
D. 模拟信号
【单选题】
：大小和方向随时间间断变化。
A. 离散信号
B. 脉冲信号
C. 数字信号
D. 模拟信号
【单选题】
数字信号即 ，也叫脉冲信号。
A. 模拟信号
B. 放大信号
C. 缩小信号
D. 离散信号
【单选题】
数字信号即离散信号，也叫 。
A. 缩小信号
B. 无线信号
C. 放大信号
D. 脉冲信号
【单选题】
绝缘栅双极晶体管（IGBT)综合了 和MOSFET的优点，因而具有良好的特性。
A. MOS
B. GTR
C. CMOS
D. BJT
【单选题】
可以将交流电整流成直流电。
A. 逆变电路
B. 整流电路
C. 滤波电路
D. 交流电路
【单选题】
整流电路它的作用是将交流电能变为直流电能供给 设备。
A. 交流用电
B. 直流用电
C. 整流用电
D. 逆变用电
【单选题】
整流电路它的作用是将 变为 供给 。
A. 直流电能、交流电能、交流用电设备
B. 交流电能、直流电能、直流用电设备
C. 交流电能、直流电能、交流用电设备
D. 直流电能、交流电能、直流用电设备
【单选题】
晶闸管在一个电源周期中处于通态的 称为导通角。
A. 角度
B. 负角度
C. 正角度
D. 电角度
【单选题】
晶闸管在一个电源周期中处于通态的电角度称为 。
A. 导电角
B. 导通角
C. 导流角
D. 正角度
【单选题】
变流电路也称斩波电路（DC Chopper）。
A. 间接直流
B. 直接直流
C. 间接交流
D. 直接交流
【单选题】
直接直流变流电路也称 （DC Chopper）。
A. 滤波电路
B. 谐波电路
C. 斩波电路
D. 整流电路
【单选题】
变流电路功能是将直流电变为另一固定电压或可调电压的直流电。
A. 间接直流
B. 直接直流
C. 间接交流
D. 直接交流
【单选题】
直接直流变流电路功能是将直流电变为另一固定电压或 的直流电。
A. 变化电压
B. 波动电压
C. 可调电压
D. 不变电压
【单选题】
：把直流电逆变成交流电的电路。
A. 整流电路
B. 滤波电路
C. 变换电路
D. 逆变电路
【单选题】
逆变电路的特点：直流侧为电压源或并联大电容，直流侧电压基本无脉动。
A. 电流型
B. 电压型
C. 电阻型
D. 电能型
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