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8.有两根长直导线ab互相平行放置,图8所示为垂直于导线的截面图。在图示的平面内,O点为两根导线连线的中点,M、N为两根导线附近的两点,它们在两导线的中垂线上,且与O点的距离相等。若两导线中通有大小相等、方向相同的恒定电流I,则关于线段M N上各点的磁感应强度的说法中正确的是  (    )

A. M点和N点的磁感应强度大小相等,方向相同

B. M点和N点的磁感应强度大小相等,方向相反

C. 在线段M N上各点的磁感应强度都不可能为零

D. 在线段M N上只有一点的磁感应强度为零

试题详情

7.图6中A是一底边宽为L的闭合线框,其电阻为R。现使线框以恒定的速度v沿x轴向右运动,并穿过图中所示的宽度为d的匀强磁场区域,已知L< d,且在运动过程中线框平面始终与磁场方向垂直。若以x轴正方向作为力的正方向,线框从图6所示位置开始运动的时刻作为时间的零点,则在图7所示的图像中,可能正确反映上述过程中磁场对线框的作用力F 随时间t变化情况的是(  )

 

试题详情

6.图4是用电流传感器(相当于电流表,其电阻可以忽略不计)研究自感现象的实验电路,图中两个电阻的阻值均为RL是一个自感系数足够大的自感线圈,其直流电阻值也为R。图5是某同学画出的在t0时刻开关S切换前后,通过传感器的电流随时间变化的图像。关于这些图像,下列说法中正确的是(   )

 

A.甲图是开关S由断开变为闭合,通过传感器1的电流随时间变化的情况

B.乙图是开关S由断开变为闭合,通过传感器1的电流随时间变化的情况

C.丙图是开关S由闭合变为断开,通过传感器2的电流随时间变化的情况

D.丁图是开关S由闭合变为断开,通过传感器2的电流随时间变化的情况

试题详情

5.一个微型吸尘器的直流电动机的额定电压为U,额定电流为I,线圈电阻为R,将它接在电动势为E,内阻为r的直流电源的两极间,电动机恰好能正常工作,则   (    )

A.电动机消耗的总功率为UI       B.电动机消耗的热功率为

C.电源的输出功率为EI          D.电源的效率为1- 

试题详情

4.平行板电容器C与三个可变电阻器R1、R2、R3以及电源连成如图3所示的电路。闭合开关S待电路稳定后,电容器C两极板带有一定的电荷。要使电容器所带电荷量增加,以下方法中可行的是(   )

A.只增大R1,其他不变  B.只增大R2,其他不变

C.只减小R3 ,其他不变  D.只减小a、b两极板间的距离,其他不变

试题详情

3.某小型水电站的电能输送示意图如图2所示,发电机通过升压变压器T1和降压变压器T2向用户供电。已知输电线的总电阻为R,降压变压器T2的原、副线圈匝数之比为4∶1,降压变压器副线圈两端交变电压u=220sin100πt V,降压变压器的副线圈与阻值R0=11Ω的电阻组成闭合电路。若将变压器视为理想变压器,则下列说法中正确的是(    )        

A.通过R0电流的有效值是20A

B.降压变压器T2原、副线圈的电压比为4:1

C.升压变压器T1的输出电压等于降压变压器T2的输入电压

D.升压变压器T1的输出功率大于降压变压器T2的输入功率   

试题详情

2.如图1所示,线圈两端与电阻相连构成闭合回路,在线圈上方有一竖直放置的条形磁铁,磁铁的S极朝下。在将磁铁的S极插入线圈的过程中(  )

A.通过电阻的感应电流的方向由ab,线圈与磁铁相互排斥

B.通过电阻的感应电流的方向由ab,线圈与磁铁相互吸引

C.通过电阻的感应电流的方向由ba,线圈与磁铁相互排斥

D.通过电阻的感应电流的方向由ba,线圈与磁铁相互吸引  

试题详情

1.使两个完全相同的金属小球(均可视为点电荷)分别带上-3Q和+5Q的电荷后,将它们固定在相距为a的两点,它们之间库仑力的大小为F1。现用绝缘工具使两小球相互接触后,再将它们固定在相距为2a的两点,它们之间库仑力的大小为F2。则F1F2之比为(    )

A.2:1     B.4:1     C.16:1      D.60:1  

试题详情

第二节   书面表达(满分30分)

近期我市对“城市无车日”开展讨论,市民此议论纷纷,褒贬不一。请你根据下表提示,用英语给“China Dairy”写一篇短文。

赞成理由
反对理由
你的观点
1.节省能源
2.保护环境
3.减少交通事故
1.上下班浪费时间
2.影响生活质量
3.影响国家税收
 
      ?

   注意:

   1.不要逐句翻译,可适当发挥,以使行文连贯;2.词数:100左右。

3.开头已给出,其部分不计入总词数内。

Dear editor

Recently, we’ve had a discussion on whether it’s acceptable to have a car-free day in our city.

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

英语听力模拟试题录音原稿

   Text 1

   M: Is this Bus 316? I want to go to the theater.

   W: Yes, but it doesn’t go to the theater. You’ll have to cross the street and take the No. 360 there.

   Text 2

   W: Good evening, sir. There is a table for two over there. This way, please.

   M: Thank you. Could I see the menu, please?

   Text 3

   W: I hear Bill was fired by his boss the other day.

   M: Oh, yes, he was quite sick and usually got to work late.

   W: Oh, no. It wasn’t that. He made a big mistake in last week’s deal with the computer company.

   Text 4

   W: Do you think the Celtics will win the NBA title tonight?

   M: I don’t think so. They are too tired after several games.

   W: You wanna bet?

   M: Yeah? How much do you wanna bet?

   W: Let’s make it 50 dollars!

   M: Deal. I’ll go for it.

   Text 5

   M: Can you type?

   W: Yes, about eighty words a minute. I have been working as a typist for fifteen years.

   M: That’s great. I can’t type more than forty five.

   Text 6

   M: Look, Jenny. I don’t understand what’s going on. You said your sister was arriving at 7:30 p.m. It’s 8:30 now.

   W: I’m sorry, Mike. I don’t understand either. Here’s Helena’s telegram. Have a look at it.

   M: Arriving Heathrow Tuesday 7:30 p.m. Can’t wait to see you? (sarcastic)Can’t wait to see you, Hmm? I can’t wait to see her. Jenny, where’s she coming from? What airline is she traveling on? What’s the flight number?

   W: I don’t know. Do you? This telegram is the only information I have.

   M: Never mind, Jenny. Let’s have a coffee. We can sit down and think about the best thing to do.

   Text 7

   W: Hi, how much do you want for this?

   M: 150 dollars.

   W: What! Don’t try to rip me off! I know what this is worth. 40 dollars, tops.

   M: No way! It cost me more than that, 120 dollars.

   W: Come on! If you don’t give me a better price, I won’t buy this from you.

   M: 110 dollars. Take it or leave it.

   W: I’ll give you 55 dollars.

   M: I can’t do that. I have to make a living. Give me 100 dollars and it’s yours.

   W: That’s still much too expensive. If that’s the lowest you’re willing to give, I’m leaving.

   M: Wait, wait! OK, 85 dollars. Final price.

   W: I’ll pay 65 dollars, final offer.

   M: You drive a hard bargain. I’m losing money on this, but alright, I’ll let you have it for 65 dollars.

   W: Thanks a lot. See you next time.

   M: Bye.

   Text 8

   W: Good morning. Housing office. Can I help you?

   M: Hi, I’m calling about the low cost housing for graduate students.

   W: Do you know it’s only available to married graduate students and their families?

   M: Yes, I... I think my wife and I may qualify, since she’s still in graduate school. But I was wondering whether there were any other requirements.

   W: Well, unless you have more than one child, you have to have a combined annual income that’s less than fifteen thousand dollars.

   M: I’m working as a part time research assistant, so that’s no problem! But right now we’re living with my wife’s parents. Does that mean we’d have to include their income, too?

   W: Not necessarily. Why don’t you stop by our office, so I can explain everything in more detail?

   M: Sure. See you this afternoon.

   Text 9

   M: Well, Mary, I already know that you like to watch movies. What other kinds of things are you interested in?

   W: I love music and dancing. As a matter of fact, I think my favorite non-work activity is dancing.

   M: I like dancing, too. Do you like disco?

   W: Sure do. So what about you? Other than traveling and dancing, tell me all about your other interests, and your hobbies.

   M: Oh, I enjoy playing sports, and I love exercising. I work out regularly to keep fit.

   W: You do look in great shape.

   M: Thanks. Actually, I have lots of hobbies. I love to stay busy. What else do you do in your spare time?

   W: I read whenever I get the chance.

   M: Oh, read. What are your favorite kinds of novels?

   W: Mystery and romance.

    M: I’ve heard it said that romance is really a mystery.

   W: Yeah. And I’ve heard that “love works in mysterious ways.”

   Text 10

Chinese hurdler Liu Xiang, former Olympic and world champion, returned to competition in style by finishing second at the Shanghai Golden Grand Prix here on Sunday. Liu’s much anticipated return after 13 months out injured was cheered by an exciting crowd of 25000 at the Shanghai Stadium. He fought back from behind to cross the finish line shoulder to shoulder with arch rival Terrence Trammell of America, silver medalist in the Berlin World Championships. China’s 110?meter?hurdle star Liu Xiang reacts after crossing the finishing line during the 110?meter?hurdle competition at the 2009 Shanghai Golden Grand Prix in Shanghai. “This competition has boosted my confidence and I am sure to improve on this performance. It showed that I am still able to come out on the track and find my former self.” The 26?year?old said. Liu trailed Trammell by at least three meters after 50 meters, but he managed to catch up in the final meters in front of the fans of Shanghai where he was born and brought up. Liu just returned to training in July after a surgery on his right Achilles tendon in the United States last December. His performance in Shanghai gave the fans hope that he has been back on the winning track.

试题详情

第一节  短文改错(共10小题;每小题1分,满分10分)

Reading English newspapers are my favorite activity. When      76.________

I entered into the high school, I began to enjoy doing such work.    77.________

Under the teacher’s help, I realize that reading English articles is     78.________

of great important. It’s a good way to improve my English.       79.________

I’ve learned many new words and expression by doing so. I      80.________

also get much information, included news about China and the      81.________

world outside. It opens my eyes widely. Which I love most is       82.________

the section about TV programs in the coming week. I dislike       83.________

reading long articles there are many new words. I will work       84.________

hard to keep on even as it’s a particularly hard task for me.        85.________

试题详情


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