问题 实验题

物理兴趣小组做“探究导体电阻大小与导体长度的关系” 实验。他们在如图所示电路中的A、B两点间接入待研究的电阻丝,电源电压恒定。忽略电阻丝电阻随温度变化的影响,待用电阻丝的规格如下表。

(1)他们应选择序号为_________________的两根电阻丝来研究;

(2)实验中,两次电流表指针均有偏转,但第二次的示数小于第一次的示数,说明第二次接入电路的电阻丝的阻值较_______(选填“大”或“小”);

(3)上面所采用的实验方法叫做__________________________;

(4)从表中所给电阻丝的规格看,还可以用这些电阻丝来做另一个探究实验,即探究导体电阻大小与导体________________________的关系,这次你应该选择序号为________________两根电阻丝来做实验

 

答案

(1)3号与4号;(2)大;(3)控制变量法;(4)横截面积;2号与4号。

阅读理解

Rita stepped into the cool, moving water. She pushed a black inner tube in front of her. She had a worried look on her face because she had never floated down a river before.

“Let me hold your tube while you climb on,” said her father. He smiled at her. “There’s not a cloud in the sky. It’s a great day to be in the river, isn’t it?”

Rita looked out across the water. People were floating by on tubes. Some talked and laughed as they floated easily down the river. Others leaned back with hats pulled over their faces. None of them looked terrified.

“We’ll stay together,” said Rita’s father. “I’ll hold on to your rope.”

“Will we go very fast?” Rita asked.

“No,” said Dad. “We’ll move slowly for a while, and then it will get a little faster near the river’s bend. Don’t worry, Rita. You’ll be fine.”

Rita looked at her tube. It gently moved up and down in the water. She saw a girl of her own age float by. The girl seemed to be having fun. Suddenly Rita’s worries disappeared.

“I’m ready to climb on and ride, Dad,” she said.

小题1:The underlined word “floated” in the reading means “________”.

A. 漂浮        B. 乘坐                C. 划船

小题2:What is Rita’s problem in this story?   

A. She doesn’t like to be in cool water.    

B. She is afraid to try something new.

C. She is worried that she will get sunburned .

小题3:What’s the weather like in the story?

A. Cloudy.      B. Rainy.              C. Sunny.

小题4:Which of these happened last in the story?

A. Rita pushed her black tube.              

B. Rita saw a girl of her own age.

C. Rita stepped into the water.

小题5:What’s the best title for this passage?

A. Rita’s Ride.          

B. Rita’s Trip.       

C. Rita’s Visit.

多项选择题