问题 实验题

(1)某实验小组在利用单摆测定当地重力加速度的试验中:

①用游标卡尺测定摆球的直径,测量结果如图所示,则该摆球的直径为        cm。

②小组成员在试验过程中有如下说法,其中正确的是         。(填选项前的字母)

A.把单摆从平衡位置拉开30度的摆角,并在释放摆球的同时开始计时

B.测量摆球通过最低点100次的时间t,则单摆周期为

C.用悬线的长度加摆球的直径作为摆长,代入单摆周期公式计算得到的重力加速度值偏大

D.选择密度较小的摆球,测得的重力加速度值误差较小

(2)某同学在探究规格为“6V,3W”的小电珠伏安特性曲线实验中:

①在小电珠介入电路前,使用多用电表直接测量小电珠的电阻,则应将选择开关旋至_______档进行测量。(填选项前的字母)

A.直流电压10V                    B.直流电流5Ma

C.欧姆× 100                     D.欧姆× 1

②该同学采用图甲所示的电路进行测量。图中R为华东变阻器(阻值范围0~20,额定电流1.0A),L为待测小电珠,V为电压表(量程6V,内阻20k),A为电流表(量程0.6A,内阻1),E为电源(电动势8V,内阻不计),S为开关。

Ⅰ.在实验过程中,开关S闭合前,华东变阻器的画片P应置于最________端;(填“左”或“右”)

Ⅱ.在实验过程中,已知各元器件均无故障,但闭和开关S后,无论如何调节滑片P,电压表和电流表的示数总是调不到零,其原因是______点至________点的导线没有连接好;(图甲中的黑色小圆点表示接线点,并用数字标记,空格中请填写图甲中的数字,如“2点至3点”的导线)

Ⅲ.该同学描绘出小电珠的伏安特性曲线示意图如图乙所示,则小电珠的电阻值随工作电压的增大而____________。(填“不变”、“增大”或“减小”)

答案

(1)①游标卡尺读数为:9mm+7×0.1mm=9.7mm=0.97cm

②把单摆从平衡位置拉开10度的摆角,在最低点开始计时,A错误

测量摆球通过最低点100次的时间t,则单摆周期为,B错误

用悬线的长度加摆球的直径作为摆长(摆长偏大),因为,所以代入单摆周期公式计算得到的重力加速度值偏大,C正确

选择密度较小的摆球,测得的重力加速度值误差较大,D错误

故选C

(2)Ⅰ.在实验过程中,开关S闭合前,华东变阻器的画片P应置于最左端,使得分压部分电压为零

Ⅱ.电压表和电流表的示数总是调不到零,其原因是滑动变阻器起不到分压作用,可能是连成限流电路了,即1点至5点的导线没有连接好;

Ⅲ.伏安特性曲线的斜率表示电阻的倒数,跟据图像可知小电珠的电阻值随工作电压的增大而增大

阅读理解

Living in a foreign culture can be exciting, but it can also be confusing(令人迷惑的). Some Americans who taught English in other countries recently talked about their experiences.

On her first day in Micronesia(密克罗尼西亚), an island in the Pacific, Lisa thought people weren’t paying any attention to her. It was hot. She went into a store and asked, “Do you have cold drinks? ” The woman there said nothing. Lisa repeated the question. Still the woman said nothing. She later learned that the woman had answered her: She had raised her eyebrows(眉毛), which in Micronesia means “yes”.

Jane remembered an experience she had in Bulgaria(保加利亚), a country in Europe. She went to a restaurant. She asked the waiter, “Do you have cabbage today?” He nodded his head. Jane waited, but the cabbage never came. In that country, a nod means “no”.

Tom had a similar problem when he arrived in India. After explaining something in class, he asked his students if they understood. Some nod and others shake. He thought some students had not understood, so he explained again. When he asked again, they did the same thing. He soon knew that his students did understand. In India, people nod and shake their heads in different ways depending on where they come from. You have to know where a person is from to understand whether they mean “yes” or “no”.

小题1:These Americans in the passage found that they__________ .

A.should go abroad for vacations

B.needed to learn foreign languages

C.should often discuss their experiences

D.had problems with communication in other countries小题2:People in Micronesia show “yes” by ________ .

A.nodding heads

B.raising eyebrows

C.shaking heads

D.saying “no”小题3:Tom misunderstood(误解)his class at first because_______ .

A.he didn’t know much about Indian culture

B.he didn’t explain everything clearly enough

C.some students didn’t speak English

D.he didn’t know where the students came from小题4:Which of the following is TRUE?

A.In Bulgaria, nodding heads means “no”.

B.Jane taught English on a Pacific island.

C.Lisa was trying to buy some cabbage.

D.In India, only shaking heads means “yes”.小题5:The passage is mainly about_________ .

A.body language in foreign restaurants

B.class discussion in Indian schools

C.different language cultures in different countries

D.English teaching in other countries

单项选择题