如图所示,理想变压器原、副线圈匝数之比为4:1,原线圈接入电压U=2202sin

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问题:

如图所示,理想变压器原、副线圈匝数之比为4:1,原线圈接入电压U=220

2
sin100πt(V)的交流电源,副线圈接一个R=27.5Ω的负载电阻.下列说法正确是(  )

A.副线圈中电压表读数为55V

B.副线圈输出电流的周期为

1
100π
s

C.原线圈中电流表的读数为0.5A

D.原线圈的输入功率为110

2W

考点:变压器的结构和原理
题型:多选题

词语开花。

(水)池  ( )池  ( )池  ( )池

( )器  ( )器  ( )器  ( )器

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阅读理解。

     The theme of the London Olympics opening ceremony will be "Isles of wonder", organizers revealed

on Friday. The title came from an amazing speech about the beauty of the island in Shakespeare's play.

     Oscar-wining filmmaker Danny Boyle, the ceremony's artistic director, said the theme was inspired by

a passage from William Shakespeare's comedy The tempest.

     Boyle, whose Slumdog Millionaire won eight Oscars, said he was trying to keep the details of the

July 27 ceremony under wraps, but he gave away the first details of the event, set to be watched by one

billion TV viewers.

     Boyle said that he had had the biggest ringing bell made in Europe, which will hang at one end of the

Olympic Stadium and be rung to start the opening ceremony. Boyle told BBC that he wanted people to

hear it for hundreds of years.

     Fellow film director Stephen Daldry, the creative director for the London Olympics opening

ceremony, told reporters the opening show would project a journey which will celebrate who we are ,

who we were and who we wish to be.

     However, Boyle admitted that London would not rival (与……匹敌) the breathtaking opening

ceremony staged at the Beijing Olympics four years ago, due to the tougher economic times.

     It was announced the ceremony in December that the budget for the opening and closing ceremonies

had been doubled to 81 million pounds.

     Boyle also promised that the ceremony would be more intimate(个人的) than the splendid

performance of drummers and dancers in Beijing's Bird's Nest stadium.

     Boyle also promised that the show would be armed with a British sense of humor.

1. What is Danny Boyle by profession?

A. An artistic director.

B. A sports officer.

C. A film director.

D. A ceremony organizer.

2. What did Boyle reveal about the London Olympics opening ceremony?

A. It will be watched by one billion TV viewers.

B. It will be started by the ringing of a big bell.

C. It will include part of the play The Tempest.

D. It will be held on July 27th, 2012.

3. According to Boyle, the London opening show will be .

A. a journey celebrating the identity

B. more impressive than the Beijing opening show

C. funded by the British government

D. presented with a British-style humor.

4. Where can you probably come across this text?

A. In a newspaper.

B. In a yearbook.

C. In a travel guide.

D. In a biography.

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十二指肠大 * * 位于十二指肠()。

A.水平部前壁

B.升部前壁

C.降部后内侧壁

D.降部后外侧壁

E.水平部后壁

题型:多选题

下列哪句对男员工仪容的表述是不对的()

A.忌留胡须,养成每天修面剃须的良好习惯

B.面部保持清洁,如戴眼镜,应保持镜片的清洁

C.保持鼻孔清洁,平视时鼻毛可稍微露于孔外

D.保持口腔清洁,不留异味,不饮酒或含有酒精的饮料

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如图所示一桥面净空:净-7+2×0.75m人行道的钢筋混凝土T梁桥,共5根主梁。计算跨径为19.5m,设有多道横隔梁。确定荷载位于跨中时各梁的荷载横向分布系数。

 

当桥上作用的活载是人群荷载,在横向影响线的竖标值为η11=0.6,η15=-0.2时,1号梁的横向分布系数mcr,最接近的数值为()。

A.0.717

B.0.547

C.0.521

D.0.486

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