问题 问答题

如图是用来“探究导体电阻与那些因素有关”所用的电路图和器材.

(1)甲实验小组想探究导体的电阻与与材料是否有关,他们可以选择导体______和______的两端分别接入电路M、N间,并记录电流表的示数I1、I2;如果I1≠I2,说明导体的电阻与材料______关.

(2)乙小组打算将导体A、C的两端分别接入电路M、N间,并记录电流表的示数IA、IC.这是为了探究导体的电阻与______是否有关,如果IA<IC,说明RA______RC(选填:“<”、“=”或“>”).

答案

(1)探究导体的电阻与与材料是否有关,应控制导体的长度与横截面积相同而材料不同,由图示可知,应选择导体A和D的两端分别接入电路,记录电流表的示数I1、I2;如果I1≠I2,说明导体的电阻与材料有关.

(2)由图示可知,A、C导体材料与长度相同而横截面积不同,因此将导体A、C的两端分别接入电路M、N间,是为了探究导体的电阻与横截面积是否有关,如果IA<IC,说明RA>RC

故答案为:(1)A;D;有;(2)横截面积;>.

单项选择题
阅读理解

阅读理解。

     Most middle school students wear uniforms. Some students like uniforms, but others don't. However,

recently, a Japanese government survey (政府调查) shows that more students in Japan like uniforms

now because school uniforms are more fashionable (时尚的) than they were before.

     I surveyed some Japanese students about what they thought about school uniforms. I asked them,

"Do you like fashionable uniforms?" There were lots of different opinions (观点, 看法).

     Hiromi said, "I like school uniforms because I don't need to choose clothes every day. I think that

fashionable uniforms are good. My high school uniform is fashionable, but there is a problem. Fashionable uniforms are too expensive."

     Miki said that she didn't like fashionable uniforms because she didn't want to spend too much money

on uniforms. She thought that the uniforms should be changed(被改变). They should be cheaper and

easier to get.

     Mitsuaki said, "I don't like school uniforms because I want to look different. I also agree that

fashionable uniforms make many students want to wear uniforms in high school. If students like

fashionable uniforms, it is good. "

1. Do more students or fewer students like uniforms in Japan now?

    _____________________________________________________________________

2. What is the question of the survey?

    _____________________________________________________________________

3. How many students' opinions are there in the passage?

    _____________________________________________________________________

4. Why does Hiromi like school uniforms?

    _____________________________________________________________________

5. Why do students not like school uniforms?

    _____________________________________________________________________