试题与答案

如图所示,处在磁感应强度为B的匀强磁场中的单匝矩线圈abcd,以恒定的角速度ω绕

题型:选择题

题目:

如图所示,处在磁感应强度为B的匀强磁场中的单匝矩线圈abcd,以恒定的角速度ω绕ab边转动,磁场方向垂直于纸面向里,线圈所围面积为S,线圈导线的总电阻为R.t=0时刻线圈平面与纸面重合,且cd边正在离开纸面向外运动.则正确的是(  )

A.时刻t线圈中电流的瞬时值icosωt

B.线圈中电流的有效值I

C.线圈中电流的有效值I=

D.线圈消耗的电功率P

答案:

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题型:阅读理解

Mr. Green worked in an office in London, but he lived in the country and came to work by train every day. The station was not very far from his office, and he always went on foot from the station to his office and back from his office to the station. Every evening he walked past a poor man near a bridge. The man sat at the road and sold matches, and there was a dog near him. There was a piece of wood round the dog’s neck, and the words “I AM BLIND” were on the piece of wood.

Mr.Green was a kind man. He always stopped and gave a penny to the man, but he did not take any of his matches. One day, Mr.Green had a lot of work in his office and left the office very late. He came to the man and his dog, but he did not stop. The poor man stood up quickly, ran after him and said, “You’re always very kind to me. Give me a penny today. I’m a poor man.” Mr.Green stopped and he was surprised. Then he said, “You’re a blind man. How did you see me?” The poor man said, “No, I’m not blind. My dog is.”

小题1:Mr.Green lived in __________.

A.London

B.the city near London

C.the country near London

D.the country not far from his office小题2:Mr.Green went to his office __________.

A.by train

B.first by train and then on foot

C.on foot

D.first on foot and then by train小题3:Every evening Mr.Green passed a poor man near a bridge__________.

A.on his way to work

B.on the way to his office

C.on his way home by train

D.on his way to the station小题4:One day Mr.Green did not stop and give the poor man a penny because__________.

A.he did not like the man

B.he was afraid of the dog

C.he worked too late

D.he hurried to catch the train小题5:-- What is the Chinese for “blind”?   -- ___________________.

A.看见的

B.聋的

C.瞎的

D.哑的

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