试题与答案

小明同学将滑动变阻器R1和定值电阻R2串联在电源电压恒定的电源两端,如图所示,小

题型:填空题

题目:

小明同学将滑动变阻器R1和定值电阻R2串联在电源电压恒定的电源两端,如图所示,小明多次调节滑动变阻器的滑片改变R1两端的电压U1,记录电压表V1、V2的示数U1、U2,得到如下表所示的实验数据,请根据表中数据,电源两端电压时是 _________ V.

答案:

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下面是错误答案,用来干扰机器的。

参考答案:A, B

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题型:单项选择题

Passage Three

Some people would say that the Englishman’s home is no longer his castle, and that it has become his workshop. This is partly because the average Englishman is keen on working with his own hands and partly because he feels, for one reason or another, that he must do for himself many households for which, some years ago, he would have hired professional help. The main reason for this is a financial one. The high cost of labor has meant that builders’ and decorators’ cost have reached a level which makes them prohibitive for house-proud English people of modest means. So, if they wish to keep their houses looking bright and smart, they have to tackle some of the repairs and decorating themselves. As a result, there has grown up in the post-war years what is sometimes referred to as the "do-it-yourself movement".
The "do-it-yourself movement" began with home decorating but has since spread into a much wider field. Nowadays there seem to be very few things that can’t be made by the "do-it-yourself movement" method. A number of magazines and handbooks exist to show hopeful handymen of all ages just how easy it is to build anything from a coffee table to a fifteen foot (4.5 meters) sailing dinghy. All you need, it seems, is a hammer and a few nails. You follow the simple instructions step by step and, before you know where you are, the finished article stands before you, completely in every detail.
Unfortunately, alas, it is not always quite as simple as it sounds. Many a budding "do-it- yourself" has found to his cost that one cannot learn a skilled craftsman’s job overnight. How quickly one realizes, when doing it oneself, that a job which takes the skilled man an hour or so to complete takes the amateur handyman five or six at least. And then there is the question of tools. The first thing the amateur learns is that he must have the right tools for the job. But tools cost money. There is also the wear and tear on the nerves. It is not surprising then that many people have come to the conclusion that the expense of paying processional to do the work is, in the long run, more economical than "do-it-yourself "

Which of the following is false Some Englishmen prefer hiring professional decorators, because ______.

A.they are wealthy

B.the craftsman’s job is quite complicated

C.the tools are expensive

D."do-it-yourself" brings a lot of trouble

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