问题 多选题

如图所示,Ll和L2是输电线,甲是电压互感器,原、副线圈匝数比为a:l;乙是电流互感器,原、副线圈匝数比为1:b;已知电压表示数为U,电流表示数为I,则(  )

A.输电线路的输送电压为aU

B.输电线路的输送电流为

I
b

C.输电线路的输送功率为abUI

D.输电线路的输送功率为UI

答案

A、由变压器原理 根据

U1
U2
=
n1
n2
 得输电线路的输送电压为U1=
n1
n2
u2=aU,故A正确.

    B、由变压器原理

I1
I2
=
n2
n1
  得输电线路的输电电流I1
n2
n1
I2=bI,故B错误.

    C、输电线路的输送功率 P=U1I1=aU?bI=abUI,故C正确.

    D、输电线路的输送功率 P=U1I1=aU?bI  故D错误  

     故选 A,C.

单项选择题 A1型题
写作题

某班级学生近期准备举行一次讨论学习习惯问题的班会活动,请你结合自身的学习实际,按以下提示,用英文写一篇发言稿。

好的学习习惯在学习中扮演了非常重要的角色,好的学习习惯能提高学习效果。

介绍一些好的学习习惯并提出养成该习惯的建议。

描述自己在学习习惯方面存在的某个问题并给出改进措施

参考词汇:学习习惯(leaning habits) 学习效果(leaning efficiency)

在……扮演重要角色(play an important role in)减少,降低 decrease

Dear students,

Learning habits is very important to everyone .

                                                                                         

                                                                                          

                                                                                         

                                                                                         

                                                                                      

                                                                                         

                                                                                    

                                                                                       

                                                                                    

                                                                                      

                                                                                         

                                                                                      

                                                                                        

Thank you