关于线圈在匀强磁场中转动产生的交变电流,以下说法中正确的是( ) A.线圈平面

题型:选择题

问题:

关于线圈在匀强磁场中转动产生的交变电流,以下说法中正确的是(   )

A.线圈平面每经过中性面一次,感应电流方向就改变一次,感应电动势方向不变

B.线圈每转动一周,感应电流方向就改变一次

C.线圈平面每经过中性面一次,感应电动势和感应电流的方向都要改变一次

D.线圈转动一周,感应电动势和感应电流方向都要改变一次

考点:交变电流的周期和频率交变电流的图像
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Three travelers, Allan, Carl and Paul were sitting on the chairs in a train station. They were waiting for a train that was very late.

To pass the time, they began talking to each other.

At first, they talked about the weather and their work. Then Paul said, "Tell me—what would you most like to do if your doctor tell you that you have only three months to live?"

The other two men thought about this for a while, then Carl spoke.

“Well,” he said, “if I have only three months to live, I’ll take all my money out of the bank and go to foreign countries for holidays with my best friend, Erik. I'd like to travel to the places in the world as many as possible. And I'll stay at the best hotels and then eat the best food. I think I'll have a wonderful time.”

“That's very interesting.” Paul said.

With these words, he turned to the other man, saying, “And what about you?”

“I'll tell you a secret,” Allan said. “I always want to be a racing driver. So if I have only three months to live, the first thing I'd like to do is to sell my house. With the money I’ll buy the fastest car in the world. Maybe I can enter all the big motor races.”

Then he laughed, "I might even end up (以……而告终) world champion.”

“Now it's your turn,” Allan went on, “If your doctor tell you the bad news, what would you most like to do?”

“Oh,” said Paul with a smile. “I’ll go and see another doctor.”

小题1:The three men were talking _____________.

A.in the post office

B.in the waiting room

C.on the train

D.on the chairs小题2:The man called ________ answered the question first.

A.Carl

B.Allan

C.Erik

D.Paul小题3:The men began to talk about the weather and the work because they __________.

A.didn't know anything new

B.wanted to pass the time quickly

C.had nothing to do

D.were very interested in each other's work小题4:"I might even end up world champion." Here the word "champion" means ___in Chinese.

A.名人

B.赛车手

C.大款

D.冠军小题5:Which sentence is right according to the passage?

A.The train didn't arrive on time.

B.Paul wanted to buy a racing car very much.

C.Allan was the second man to answer the question.

D.Carl didn't like traveling at all.

题型:选择题

()多用于管接头与壳体的连接.

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当锤式破碎机的()与锤头之间的间隙小于12mm时,可以保证破碎效率。

A.圆辊

B.反击板

C.主篦子

D.机壳

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公安决策者素质的作用是什么?

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需更换轨道电路绝缘时,应在确认扼流变压器连接线和相邻两轨道扼流变压器()等各部位连接良好后,方准开始更换作业。

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