问题 实验题

某同学根据如图提供的实验器材测灯泡的功率。

(1 )画出电路图

(2 )根据提供的实验器材为测量标有2.5V 的小灯泡,请把器材连成实验电路。

(3 )实验中要特别注意:  

①连接电路时开关必须________;

②为了保证用电器的安全,闭合开关之前先调整变阻器的滑片,使它处于在电路中阻值   ________ 

③为了提高准确程度电压表选   ___       量程,电流表选      ____   量程。

④接通电源后通过变阻器把电压调到    ___  V ,小灯泡正常发光,测出灯泡通过的电流。

⑤下面是一位同学利用正确的电路图测量小灯泡的功率时得到的数据。依据公式      _____   和测量的数据求它们的对应电功率。请把表格填写完整。

⑥实验得出,用电器的功率由加在它两端的  _________    决定。

答案

(1)

(2)

(3)①断开②最大值。 ③0~3V,0~0.6A。④2.5V。⑤P=UI、0.75、0.4、1.02。⑥电压 。

单项选择题 A1型题
阅读理解

阅读理解

     Baths and bathing have long been considered of medical importance to man. In Greece there are the

ruins(废墟) of a water system(系统) for baths built over 3,000 years ago. The Romans had warm public

baths. In some baths, as many 3,000 persons could bathe at the same time.

     Treating disease by taking bathing has been popular for centuries. Modern medical bathing first became popular in Europe and by the late 1700's has also become popular in the United States.

     For many years frequent(经常的) bathing was believed to be bad for one's health. Ordinary bathing

just to keep clean was avoided(避免), and perfume was often used to cover up body smells!

     By the 1700's doctors began to say that soap and water were good for health. They believed that it

was good for people to be clean. Slowly, people began to bathe more frequently. During the Victorian

Age of the late 19th century, taking a bath on Saturday night became common.

     In the United States ordinary bathing was slow to become popular. During the 18th and early 19th

centuries, many Americans were known as "The Great Unwashed!" In one American city, for example, a

person was only allowed to take a bathe every thirty days! That was a law!

     Frequency of bathing today is partly a matter of habit. People know that bathing for cleanliness is

important to health. Doctors know that dirty bodies increase the chance of diseases. As a result, in the

United States, people generally bathe often. Some people bath once a day at least. They consider a daily

bath essential (=necessary) to good health.

1. A water system for baths was built by    over 3,000 years ago.

A. the Romans  

B. the Greeks      

C. the Americans      

D. the Europeans

2. The underlined word perfume probably means     .

A. something smelling sweet      

B. good health

C. something smelling strange      

D. large wealth

3. In the 18th century doctors believed that being clean was     .

A. unimportant    

B. good for health    

C. harmful    

D. important

4. Which of the following gives the main idea of the passage?

A. Everybody in America takes a daily bath.

B. A bath a day keeps the doctor away.

C. Taking baths has become popular in the world.

D. Bathing has become easier and cheaper

5. Dirty bodies can        .

A. ruin one's business

B. cause good health

C. drive customers away            

D. cause disease