问题 实验题

某同学通过查找资料自己动手制作了一个电池。该同学想测量一下这个电池的电动势E和内电阻r,但是从实验室只借到一个开关、一个电阻箱(最大阻值为9.999Ω,科当标准电阻用) 一只电流表(量程IR=0.6A,内阻rg=0.1Ω)和若干导线。

(1)请根据测定电动势E内电阻r的要求,设计图1中器件的连接方式,画线把它们连接起来。

(2)接通开关,逐次改变电阻箱的阻值R,读出与R对应的电流表的示数I,并作记录当电阻箱的阻值R=2.6Ω时,其对应的电流表的示数如图2所示。处理实验数据时首先计算出每个电流值I的倒数,再制作R-坐标图,如图3所示,图中已标注出了()的几个与测量对应的坐标点,请你将与图2中实验数据对应的坐标点也标注在图3中上。

  

(3)在图3上把描绘出的坐标点练成图线。

(4)根据图3描绘出的图线可得出这个电池的电动势E=____________V,内电阻r=____________Ω。

答案

(1)

(2)(3)

(4)1.5(1.46~1.54),0.3(0.25~0.35)

阅读理解

阅读理解。

   An Englishman was once travelling in Italy. He could not speak Italian. One day he went to a restaurant

and sat at a table. When the waiter came, the Englishman opened his mouth, put his fingers (手指) into it,

took them out again and moved his lips (嘴唇). In this way he meant to say, "Bring me something to eat."

The waiter soon brought him a cup of tea. The Englishman shook his head and the waiter understood that

he didn't want tea, so he took it away and brought him some coffee. The Englishman was very hungry

now and looked very sad. He was just going to leave the restaurant when another man came in. That man

put his hands on his stomach. That was good enough for the waiter. In a few minutes the waiter brought

him a large plate of bread and meat.

1.One day the Englishman went to a restaurant to           . [ ]

A.have a rest

B.learn some Italian

C.get something to drink

D.get something to eat

2.When the waiter came up to him, the Englishman           . [ ]

A.looked around the restaurant and sat down on a table

B.wanted to show that he wanted to eat something

C.told the waiter he was hungry

D.made signs to show that he was sad

3.When the waiter brought him a cup of tea, the Englishman           . [ ]

A.moved his head from side to side

B.saw a man come in with his hand on his stomach

C.took his fingers out of the mouth and moved his lips

D.took it over

4.Why did the waiter take the tea away? [ ]

A.Because the Englishman liked coffee best

B.Because the Englishman looked very sad

C.Because the Englishman didn't pay for it

D.Because he understood the Englishman didn't want it

5.Which of the following sentences is right? [ ]

A.Another man brought him a large plate of bread and meat.

B.The Englishman bought a large plate of bread and meat.

C.Another man got a large plate of bread and meat.

D.The waiter found a large plate of bread and meat on the table.

单项选择题