【单选题】【消耗次数:1】
容量lOOkVA以上的变压器,一次熔丝额定电流应按变压器一次额定电流的( )倍选择。
1~1.5
1.5~2
2~3
3~5
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相关题目
【判断题】 变压器的额定容量就是原绕组的额定电压与额定电流的乘积
①  正确
②  错误
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【单选题】 有一台三相电力变压器容量S=400kVA;额定电压10/0.4kV,其一次额定电流计算值约为( )A。
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②  5.77
③  57.7
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②  错误
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①  正确
②  错误
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①  正确
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【单选题】 若变压器的一次侧电源频率升高,电压幅值不变,变压器的励磁电流将( )。
①  升高
②  降低
③  不变
【单选题】 若变压器的一次绕组匝数减少而电压幅值不变,变压器的励磁电流将( )。
①  升高
②  降低
③  不变
【单选题】 当变压器一次侧电压一定时,若二次侧电流增大,则一次侧电流将( )。
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随机题目
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【单选题】 菜单控件只有一个事件( )。
①  MouseUp
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①  45
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【单选题】 阅读理解:阅读下列短文,回答文后问题,选择最佳答案Robert had just moved into the street and he felt strange that he was not wanted. He knew that perhaps the other boys were trying to get an idea of what kind of a boy he was. This did not help him to make himself less lonely. He was new and he had to be tested. Still, proving himself would not be all that easy. He did not want to run with the boys or get into something against the law to prove that he was strong. No! He must show what he was made of in a more helpful way. That’s when he got the idea.The next day was Saturday. He knew that most of the boys would be down on the playground and choose up sides for the Saturday game. Robert knew he could play well and that just might be enough to prove he was strong, and to make friends with them. He arrived early and did his step exercises. He shot the ball several times and did some other exercises—the most difficult and most wonderful in basketball. Then the boys came. Robert went through what he had done before the game and showed what he could do. No one said a word. The boys just looked at each other and thought about it. In the end, when it was all over, the biggest of the group just smiled and shook his head. Robert knew he had made it.4. What did the biggest of the group mean by shaking his head?
①  He did not want to say anything about what Robert had done.B. He had not thought Robert could play so wonderfully.C. He did not want to make friends with Robert.D. He did not think Robert played basketball well.
②  He had not thought Robert could play so wonderfully.
③  He did not want to make friends with Robert..
④  He did not think Robert played basketball well.
【单选题】 阅读理解:阅读下列短文,回答文后问题,选择最佳答案Robert had just moved into the street and he felt strange that he was not wanted. He knew that perhaps the other boys were trying to get an idea of what kind of a boy he was. This did not help him to make himself less lonely. He was new and he had to be tested. Still, proving himself would not be all that easy. He did not want to run with the boys or get into something against the law to prove that he was strong. No! He must show what he was made of in a more helpful way. That’s when he got the idea.The next day was Saturday. He knew that most of the boys would be down on the playground and choose up sides for the Saturday game. Robert knew he could play well and that just might be enough to prove he was strong, and to make friends with them. He arrived early and did his step exercises. He shot the ball several times and did some other exercises—the most difficult and most wonderful in basketball. Then the boys came. Robert went through what he had done before the game and showed what he could do. No one said a word. The boys just looked at each other and thought about it. In the end, when it was all over, the biggest of the group just smiled and shook his head. Robert knew he had made it.2. Why would it not be easy for Robert to prove himself?
①  Because he was not sure if he was really strong.
②  Because he was new and was not wanted in the street.
③  Because the other boys had found out what kind of a boy he was.
④  Because he must choose the best way to prove himself.
【单选题】 阅读理解:阅读下列短文,回答文后问题,选择最佳答案Robert had just moved into the street and he felt strange that he was not wanted. He knew that perhaps the other boys were trying to get an idea of what kind of a boy he was. This did not help him to make himself less lonely. He was new and he had to be tested. Still, proving himself would not be all that easy. He did not want to run with the boys or get into something against the law to prove that he was strong. No! He must show what he was made of in a more helpful way. That’s when he got the idea.The next day was Saturday. He knew that most of the boys would be down on the playground and choose up sides for the Saturday game. Robert knew he could play well and that just might be enough to prove he was strong, and to make friends with them. He arrived early and did his step exercises. He shot the ball several times and did some other exercises—the most difficult and most wonderful in basketball. Then the boys came. Robert went through what he had done before the game and showed what he could do. No one said a word. The boys just looked at each other and thought about it. In the end, when it was all over, the biggest of the group just smiled and shook his head. Robert knew he had made it.1.What does “This did not help to make him less lonely” mean?
①  Robert felt more lonely because the other boys wanted to test him.
②  Robert did not want himself to be less lonely.
③  Robert felt as lonely as before when the other boys tried to find out what kind of a boy he was.
④  The other boys did not want to make Robert feel less lonely.
【单选题】 阅读理解:阅读下列短文,回答文后问题,选择最佳答案Robert had just moved into the street and he felt strange that he was not wanted. He knew that perhaps the other boys were trying to get an idea of what kind of a boy he was. This did not help him to make himself less lonely. He was new and he had to be tested. Still, proving himself would not be all that easy. He did not want to run with the boys or get into something against the law to prove that he was strong. No! He must show what he was made of in a more helpful way. That’s when he got the idea.The next day was Saturday. He knew that most of the boys would be down on the playground and choose up sides for the Saturday game. Robert knew he could play well and that just might be enough to prove he was strong, and to make friends with them. He arrived early and did his step exercises. He shot the ball several times and did some other exercises—the most difficult and most wonderful in basketball. Then the boys came. Robert went through what he had done before the game and showed what he could do. No one said a word. The boys just looked at each other and thought about it. In the end, when it was all over, the biggest of the group just smiled and shook his head. Robert knew he had made it.Which of the following is the best title for this passage?
①  Ways to Prove Oneself.
②  Robert Is Lonely.
③  Just One of the Boys. D.
④  A Saturday Basketball