0  253696  253704  253710  253714  253720  253722  253726  253732  253734  253740  253746  253750  253752  253756  253762  253764  253770  253774  253776  253780  253782  253786  253788  253790  253791  253792  253794  253795  253796  253798  253800  253804  253806  253810  253812  253816  253822  253824  253830  253834  253836  253840  253846  253852  253854  253860  253864  253866  253872  253876  253882  253890  447090 

Section A

Directions: In Section A, you will hear ten short conversations between two speakers. At the end of each conversation, a question will be asked about what was said. The conversation and the question will be spoken only once. After you hear a conversation and the question about it, read the four possible answers on your paper, and decide which one is the best answer to the question you have heard.

1.  A. At a car shop.    B. In a garage.  

C. At a gas station.     D. In a parking lot.

2.  A. Guest and receptionist.        B. Passenger and air hostess.

C. Customer and shop assistant.        D. Guest and waitress.

3.  A. Writing his term paper.        B. Having a coffee break.

C. Playing computer games.        D. Attending an online school.

4.  A. To the bank. B. To a book store.   C. To a shoe store.   D. To the grocery.

5.  A. Touring around.             B. Looking for a job. 

C. Visiting a couple.          D. Attending a meeting.

6.  A. He's better.      B. He's feeling worse. 

C. He's sick in bed.   D. He has recovered.

7.  A. He works as a gardener.        B. He is too busy at work to play.

C. He prefers sports to gardening.    D. He lives in the countryside.

8.  A. Buy a road map.            B. Drive to the beach.

C. Go back home.             D. Ask the way.

9.  A. The film was disappointing.      B. The leading actor was outstanding.

C. The acting was worth seeing.     D. The plot was attractive.

10. A. He is always late for work.        

B. He is having some financial problem.

C. He is not careful enough with his work. 

D. He loses his temper easily.

Section B

Directions: In Section B, you will hear two short passages, and you will be asked three questions on each of the passages. The passages will be read twice, but the questions will be spoken only once. When you hear a question, read the four possible answers on your paper and decide which one would be the best answer to the question you have heard.

Questions 11 through 13 are based on the following passage.

11. A. Her husband had got a higher position.  B. Her husband had lost his job.

C. She wanted to have a cleaner house.    D. She wanted to move to New York.

12. A. His watch went out of order.     B. The buyers had to leave soon.

C. He began to work at 8 a.m.        D. He wanted to give the speaker a surprise.

13. A. Because the husband told a joke.   B. Because they were amazed at the house.

C. Because the woman looked funny.    D. Because they saw something familiar.

Questions 14 through 16 are based on the following passage.

14. A. 80 per cent. B. 73 per cent.   C. 68 per cent.   D. 19 per cent.

15. A. The drivers have little time to do many things.

   B. The drivers may risk people’s lives by doing this.

C. The drivers can’t concentrate on every thing they do.

D. The drivers may break the traffic regulations.

16. A. Young people should not be allowed to multi-task.

B. Americans have no choice but multi-task to save time.

C. people should do no more than drive while driving.

D. People can only multi-task in their homes and offices.

Section C

Directions: In Section C, you will hear two longer conversations. The conversations will be read twice. After you hear each conversation, you are required to fill in the numbered blanks with the information you have heard. Write your answers on your answer sheet.

Blanks 17 through 20 are based on the following conversation.

A telephone message
Caller:  Jake Green from (17) ____________ Office Supplies
Subject: To fax the information about after-sales (18) ______________ at about (19) ___________ p.m.
Telephone number: 560-1827
Fax number: (20) ___________________

Complete the form. Write ONE WORD for each answer.

Blanks 21 through 24 are based on the following conversation.

What is Susan holding in her hand?
(21) ____________.
What does the man think of tobacco companies?
They are good at (22) ____________.
What do tobacco commercials for women focus on?
They focus on (23) ___________ themes as if smoking is closely related to (24) ____________.

Complete the form. Write NO MORE THAN THREE WORDS for each answer.

试题详情

30.湖南省雅礼中学2010届高三上学期第五次月考一个直流电动机的内电阻,与R=8的电阻串联接在线圈上,如图所示。已知线圈面积为m2,共100匝,线圈的电阻为2欧,线圈在T的匀强磁场中绕O以转速n=600r/min匀速转动时,在合上开关S后电动机正常工作时,电压表的示数为100V,求电动机正常工作时的输出功率。

解:线圈转动时产生的电动势的最大值为:

  V       (2分)

有效值为:V       (1分)

设线圈的电阻为,则电路中的电流IA    (2分)

电动机正常工作时的输出功率为W   (3分

试题详情

29.贵州省兴义市清华实验学校2010届高三9月月考一座小型水电站发电机输出功率为100kW,输出电压为500V。输电线的电阻为10Ω,允许功率损耗为输出功率的4%  ,用电单位需要220V电压。求:所用升压变压器和降压变压器的原、副线圈的匝数比各为多少?

解:由题意得:   I1=P/ U1=200A  I22R=P× 4% ,  I2=20A 

所以升压变压器原、副线圈的匝数比:n1/n2=I2/I1=1/10 

U2=U1n2/n1=5000v  U3=U2-I2R=4800v  所以降压变压器原、副线圈的匝数比:

n3/n4=U3/U4=240/11 

试题详情

28.贵州省兴义市清华实验学校2010届高三9月月考如图是一种自行车上照明用的车头灯发电机的结构示意图,转轴的一端装有一对随轴转动的磁极,另一端装有摩擦小轮。电枢线圈绕在固定的U形铁芯上,自行车车轮转动时,通过摩擦小轮带动磁极转动,使线圈中产生正弦交流电,给车头灯供电。

已知自行车车轮半径r=35cm,摩擦小轮半径r0=1.00cm,线圈有n=800匝,线圈横截面积s=20cm2,总电阻R1=40Ω,旋转磁极的磁感应强度B=0.010T,车头灯电阻R2=10Ω。当车轮转动的角速度ω=8rad/s时。求:

  (1)发电机磁极转动的角速度。

  (2)车头灯中电流的有效值。

解:(1)磁极与摩擦小轮转动的角速度相等,由于自行车车轮与摩擦小轮与摩擦小轮之间无相对滑动,故有     ①

    ②

(2)摩擦小轮带动磁极转动,线圈产生的感应电动势的最大值为

 ③

感应电动势的有效值    ④

通过电流的有效值   ⑤

试题详情

27.四川省宜宾市2010届高三摸底测试如图所示,某理想变压器的原线圈接一交流电(V),副线圈接如图所示的电路(图中电表均为理想交流电表),且R1 = R2。电键S原来为闭合,现将S断开,则电压表的示数U ____(选填“增大”、“保持不变”或“减小”,下同)。变压器原线圈的输入功率P____。

答案:  增大   减小

试题详情

26.河南省南召二高2010届高三上学期期末模拟某理想变压器初、次级匝数比为55:9,初级接压V的交流电源上,则与次级并联的电压表的读数为_______V,当次级接上60的电灯一盏时,变压器输入功率为_________W。

答案:36   21.6

试题详情

25.广东省汕尾市2010届高三上学期期末调研考试用电高峰期,电灯往往会变暗,其原理可简化为如下物理问题.如图,理想变压器的副线圈上,通过输电线连接两只相同的灯泡L1L2,输电线的等效电阻为R,原线圈输入有效值恒定的交流电压,当开关S闭合时,以下说法正确的是  (  AD  )

A.灯泡L1两端的电压减小

B.原线圈输入功率减小

C.副线圈输出电压减小

D.电阻R两端的电压增大

试题详情

24. 江苏省田家炳实验中学2010届高三上学期期末模拟某交流发电机给灯泡供电,产生正弦式交变电流的图象如图所示,下列说法中正确的是(  D  )

A.交变电流的频率为0.02Hz

B.交变电流的瞬时表达式为

C.在t=0.01s时,穿过交流发电机线圈的磁通量最大

D.若发电机线圈电阻为0.4Ω,则其产生的热功率为5W

试题详情

23.福建省厦门外国语学校2010届高三第三次月考矩形金属线圈共10匝,绕垂直磁场方向的转轴在匀强磁场中匀速转动,线圈中产生的交流电动势e随时间t变化的情况如图所示.下列说法中正确的是 (  D  )

A.此交流电的频率为0.2Hz

B.此交流电动势的有效值为1V

C.t=0.1s时,线圈平面与磁场方向平行

D.t=0.1s时,通过线圈的磁通量最大

试题详情

22.湖南省雅礼中学2010届高三上学期第五次月考如图所示,理想变压器的副线圈上通过输电线接有三个灯炮L1L2L3,输电线的等效电阻为R,原线圈接有一个理想的电流表,开始时,开关S接通,当S断开时,以下说法中正确的是  (  D  )

A.原线圈两端PQ间的输入电压减小  

B.等效电阻R上消耗的功率变大

C.原线圈中电流表示数增大        

D.灯炮L1L2变亮

试题详情


同步练习册答案