问题 实验题

实验:回答下列问题,测定电流表内阻的实验中备用的器材有

A.电流表(量程100μA)

B.电阻箱(阻值范围0~9999Ω)

C.电阻箱(阻值范围0~99999Ω)

D.电源(E=6V,有内阻)

导线和电键若干

(1)如果采用如图所示的电路测定电流表A的内阻,并且要得到较好精度,那么从以上的器材中,可变电阻R1应选_________,R2应选_________(用字母代号填空)。

(2)如果实验时要进行的步骤有:

A.合上K1;     

B.合上K2

C.观察R1的阻值是否最大,若不是,将R1的阻值调至最大;

D.调节R1的阻值,使电流表指针偏转至满刻度;

E.调节R2的阻值,使电流表指针偏转到满刻度的一半;

F.记下R2的阻值。

把以上步骤的字母代号按实际的合理顺序填在下面横线上_________。

(3)如果在步骤F中所得R2的阻值为600Ω,则图中电流表内阻Rg的测量值为_________。如果要将第(1)小题中电流表改装成量程为0~5V的电压表,则改装的方法是将电流表串联一个阻值为_________Ω的电阻。该实验测得的电流表内阻Rg测_________Rg真(填“大于”、“小于”或“等于”)。

答案

(1)C,B    

(2)CADBEF  

(3)600Ω,4.94×104,小于

写作题

阅读理解。

    Bob comes out of the station and he doesn't know where to go. This is the first time he comes to this town. He comes to see his good friend, Peter. Peter is a worker. He works in a factory, but Bob doesn't know where the factory is. He walks in the street. He passes a hospital(医院), a post office, a bookshop and at last he gets to a school. Some students are coming out. So he asks one of them for help. "Excuse me, do you know where the watch factory is?"

   "Of course. I know. I live near there. My father works there. It's outside the town."

   "Is it far from here? Can you show me the way, please?"

   "It's about 8 kilometers away from here, I'm going home now, will you go with me? I'll take you there."

   "That's great! Thank you very much."

   "Now let's take a No.10 bus. It'll take about 15 minutes to get there."

   "Thank you," says Bob.                               

1. Bob goes to a town to _________.

A.look for a job            

B.see a student        

C.see his friend            

D. work in a factory      

2. Peter works in a _________.

A.school          

B.hospital          

C.post office    

D. factory

3. The watch factory is _________.

A. in the middle of the town        

B. outside the twon

C. near the school

D. between a hospital and a bookshop

4. Bob and the student go to the factory _________.

A.on foot        

B.by car            

C. by bus      

D. by taxi

5. They need to catch _______.

A. a number 8 bus        

B. a number 10 bus          

C. a number 15 bus        

D. a train

填空题