2022年2022届高考物理必考知识点总结复习：交流电 .pdf

高考物理知识点总结：复习交流电知识要点：1、交流电2、基本要求：（1）理解正弦交流电的产生及变化规律矩形线圈在匀强磁场中，从中性面开始旋转，在已知B、L、情况下，会写出正弦交流电的函数表达式并画出它的图象。函数表达式与图象相互转换。（2）识记交流电的物理量，最大值、瞬时值、有效值；周期、频率、角频率；（3）理解变压器的工作 原理及初级，次级线圈电压，电流匝数的关系。理解远距离输电的特点。（4）了解三相交流电的产生。一、交流电的产生及变化规律：1、产生：强度和方向都随时间作周期性变化的电流叫交流电。矩形线圈在匀强磁场中，绕垂直于匀强磁场的线圈的对称轴作匀速转动时，如图51 所示，产生正弦（或余弦）交流电动势。当外电路闭合时形成正弦（或余弦）交流电流。图 51 2、变化规律：（1）中性面：与磁力线垂直的平面叫中性面。线圈平面位于中性面位置时，如图52（A）所示，穿过线圈的磁通量最大，但磁通量变化率为零。因此，感应电动势为零。图 52 当线圈平面匀速转到垂直于中性面的位置时（即线圈平面与磁力线平行时）如图 52（C）所示，穿过线圈的磁通量虽然为零，但线圈平面内磁通量变化率最大。因此，感应电动势值最大。mNBlvNBS2 （伏）（N 为匝数）（2）感应电动势瞬时值表达式：若从中性面开始，感应电动势的瞬时值表达式：etm sin（伏）文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4如图 52（B）所示。感应电流瞬时值表达式：iItm sin（安）若从线圈平面与磁力线平行开始计时，则感应电动势瞬时值表达式为：etm cos（伏）如图 52（D）所示。感应电流瞬时值表达式：iItm cos（安）3、交流电的图象：etm sin图象如图 53 所示。etm cos图象如图 54 所示。想一想：横坐标用t 如何画。4、发电机：发电机的基本组成：线圈（电枢）、磁极种类旋转电枢式发电机转子电枢定子磁极旋转磁极式发电机转子磁极定子电枢旋转磁极式发电机能产生高电压和较大电流。输出功率可达几十万千瓦，所以大多数发电机都是旋转磁极式的。二、表征交流电的物理量：文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U41、瞬时值、最大值和有效值：交流电在任一时刻的值叫瞬时值。瞬时值中最大的值叫最大值又称峰值。交流电的有效值是根据电流的热效应规定的：让交流电和恒定直流分别通过同样阻值的电阻，如果二者热效应相等（即在相同时间内产生相等的热量）则此等效的直流电压，电流值叫做该交流电的电压，电流有效值。正弦（或余弦）交流电电动势的有效值和最大值m的关系为：mm20707.交流电压有效值UUm.0 707；交流电流有效 值IIm.0 707。注意：通常交流电表测出的值就是交流电的有效值。用电器上标明的额定值等都是指有效值。用电器上说明的耐压值是指最大值。2、周期、频率和角频率交流电完成一次周期性变化所需的时间叫周期。以T 表示，单位是秒。交流电在 1 秒内完成周期性变化的次数叫频率。以f 表示，单位是赫兹。周期和频率互为倒数，即Tf1。我国市电频率为 50 赫兹，周期为 0.02秒。角频率：22Tf单位：弧度/秒文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4三、三相交流电：1、三个互成 120 的三个相同线圈，固定在同一转轴上，在同一匀强磁场中作匀速转动，将产生三个交变电动势，所产生的电流叫做三相交流电。由于这三个线圈是相同的，因此，它们将产生三个依次达到最大值的交变电动势。相当于三个最大值和周期都相同的独立电源。2、每个独立电源称作“一相”，虽然每相的电动势的最大值和周期都相同，但是它们不能同时为零或者同时达到最大值。由于三个线圈的平面依次相差120 角，它们到达零值和最大值的时间依次落后13周期。如图 55 所示。3、在实际应用中，三相发电机和负载并不用六条导线相连接，而是采用“Y”和“”两种接法。有兴趣的同学可以参阅必修本P116*部分内容。四、变压器：1、变压器是可以用来改变交流电压和电流的大小的设备。理想变压器的效率为1，即输入功率等于输出功率。对于原、副线圈各一组的变压器来说（如图56），原、副线圈上的电压与它们的匝数成正。即UUnn1212因为有UIUI1122，因而通过原、副线圈的电流强度与它们的匝数成反比。文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4即IInn1221注意：对于副线圈有两组或两组以上的变压器来说，原、副线圈上的电压与它们的匝数成正比的规律仍然成立，但各副线圈的电流则应根据功率关系PP入出，去 计 算 各 线 圈 的 电 流 强 度，即UIUIUI112233。当副线圈不接负载（外电路断开时）I2=0，P出0，因此PI入，001。当副线圈所接负载增多时，由于通常负载多是并联使用，因此，总电阻减少，使I2增大，输出功率增大，所以输入功率变大。因为PP入出，即UIUI1122，所以变压器中高压线圈电流小，绕制的导线较细，低电压的线圈电流大，绕制的导线较粗。上述各公式中的I、U、P 均指有效值，不能用瞬时值。2、远距离送电：由于送电的导线有电阻，远距离送电时，线路上损失电能较多。在输送的电功率和送电导线电阻一定的条件下，提高送电电压，减小送电电流强度可以达到减少线路上电能损失的目的。线路中电流强度I 和损失电功率计算式如下：IPUPIR输出损线2注意：送电导线上损失的电功率，不能用PUR损出线2求，因为U出不是全部降落在导线上。文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4例 12011山东卷 T20 为保证用户电压稳定在220 V，变电所需适时进行调压，图 15 甲为调压变压器示意图保持输入电压u1不变，当滑动接头 P 上下移动时可改变输出电压 某次检测得到用户电压 u2随时间 t 变化的曲线如图 15 乙所示以下正确的是()图 15 Au2190 2sin(50 t)V Bu2190 2sin(100 t)V C为使用户电压稳定在220 V，应将 P 适当下移D为使用户电压稳定在220 V，应将 P 适当上移【解析】BD由图乙可知，交变电流的最大值为190 2V，周期为 0.02 s，2T100 rad/s，所以 A 项错误，B 项正确为了让用户得到 220 V 的电压，由u1u2n1n2可知，要想使电压u2升高，n1必须变小，C 项错误，D 项正确例 22011四川卷 T20 如图所示，在匀强磁场中匀速转动的矩形线圈的周期为T，转轴 O1O2垂直于磁场方向，线圈电阻为2.从线圈平面与磁场方向平行时开始计时，线圈转过60 时的感应电流为 1 A那么()A线圈消耗的电功率为4 W B线圈中感应电流的有效值为2 A 文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4C任意时刻线圈中的感应电动势为e4cos2TtD.任意时刻穿过线圈的磁通量为Tsin2Tt【解析】AC当线圈从图示位置开始计，此时交变电流的瞬时值表达式为 iImcos t，当 t60 时，i1 A，可解得 Im2 A，其有效值为 IIm22 A，B 错误；回路消耗的功率PI2R4 W，A正确；线圈中感应感应电动势的最大值EmImR4 V，所以任意时刻线圈中的感应电动势为e4cos 2Tt，C 正确；磁通量的最大值mBSBSEm42T，则穿过线圈任意时刻的磁通量2Tsin 2Tt，D 错误文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R10 ZS1Z3X9F8U4文档编码:CV3R8Z5M9W4 HL2M2P2L2R