LFP—901A型保护在非全相运行再发生故障时,阻抗继电器开放,开放保护的判据为()

题型:多项选择题

问题:

LFP—901A型保护在非全相运行再发生故障时,阻抗继电器开放,开放保护的判据为()

A、非全相运行再发生单相故障时,以选相区不在跳开相时开放;

B、当非全相运行再发生相间故障时,测量非故障两相电流之差的工频变化量,当电流突然增大达一定幅值时开放;

C、非全相运行再发生单相故障时,以选相区在跳开相时开放;

D、当非全相运行再发生相间故障时,测量非故障两相电压之差的工频变化量,当相间电压差突然减小达一定幅值时开放;

考点:继电保护工考试继电保护工考试题库
题型:多项选择题

阅读理解。

     Last Friday a storm swept through two villages in the New Territories, destroying fourteen homes.

Seven others were so badly damaged (破坏) that their owners had to leave them, and fifteen others

had broken windows or broken roofs. One person was killed, several were badly hurt and taken to

hospital, and a number of other people received smaller hurt. Altogether (总共) over two hundred

people were homeless after the storm.

      A farmer, Mr. Tan, said that the storm began early in the morning and lasted for over an hour.

     "I was eating with my wife and children," he said, "when we heard a loud noise. A few minutes later

our house fell down on top of us. We tried our best to climb out but then I saw that one of my children

was missing. I went back inside and found him, safe but very frightened."

     Mrs. Woo Mei Fong said that her husband had just left for work when she felt that her house was

moving. She ran outside at once with her children.

     "There was no time to take anything," she said, "A few minutes later, the roof came down."

     Soldiers helped to take people out of the flooded (水淹的) area and the welfare department (福利

机构) brought them food, clothes and shelter.

1. How many homes altogether were damaged in the storm?

A. Fourteen.

B. Twenty-one.

C. Twenty-nine.

D. Thirty-six.

2. Where was Mr. Tan when the storm first began?

A. He was in bed.                                  

B. He was inside the house.

C. He was outside the house.                

D. He was on the roof.

3. Mrs. Woo and her family didn't get hurt because ________.

A. her husband knew there would be a storm

B. they were all outside the house when the storm became worse

C. she felt the house moving and they ran out immediately

D. the welfare department helped her

4. The underlined word "shelter" in the last paragraph means ________.

A. something to eat

B. something to wear

C. somewhere to study

D. somewhere to stay

5. Which of the following may be the best title for this passage?

A. A Terrible Storm

B. A Lucky Woman

C. Good Soldiers

D. Clever People

题型:多项选择题

缓释制剂的类型有()。

A.骨架分散型

B,缓释膜剂

C.缓释乳剂

D.缓释微囊

E.膜控型

题型:多项选择题

数据仓库中的数据面向______组织数据。

A.应用
B.主题
C.过程
D.对象

题型:多项选择题

同一税务机关违反规定,在一个纳税年度内,对统一纳税人就同一事项实施超过几次纳税评估的,会使纳税人认为税务机关未依法执行现行税收法律发给()。

A、4

B、3

C、2

D、1

题型:多项选择题

飞机飞行50KM用了时间18分钟,计算出的速度约为()。

A.184KM/H

B.167KM/H

C.150KM/H

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