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问题 实验题

（1）一位同学在实验中分别用游标卡尺和螺旋测微器测量物体长度，得到结果如图所示，游标卡尺示数________________ cm，螺旋测微器示数_______________ cm．

（2）某物理实验小组利用实验室提供的器材测量一待测电阻的阻值。可选用器材的代号和规格如下：

电流表A1 (量程250mA，内阻r1为 20Ω)；

电流表A2 (量程300mA，内阻r2约为15Ω)

待测电阻Rx（阻值约为100Ω)；

滑动变阻器R（最大阻值10Ω)；

电源E (电动势约为9V,内阻r约为1Ω)；

单刀单掷开关S，导线若干。

①请在右边的方框中把电流表的代号A1、A2填在相应的中，并且把实验电路原理图连接完整；

②需要直接测量的物理量是________，被测电阻的计算式为Rx=___________。

答案

（1）1.050；1.0446（2）①电路图见解析；②两电流表读数分别为I1、I2；

题目分析：（1）游标卡尺示数1.0cm+10×0.05mm=1.050cm，螺旋测微器示数10.0mm+0.01×44.6mm="10.446mm=1.0446" cm．(2)①电路如图示：②设两电流表读数分别为I1、I2,根据欧姆定律得，解得

单项选择题

治疗阵发性室上性心动过速的最佳钙拮抗药是

A．尼莫地平

B．维拉帕米

C．地尔硫卓

D．硝苯地平

E．氨氯地平
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单项选择题

To persuade consumers to buy more of its cameras, the PictureSharp Camera company has launched an advertising campaign in coordination with its dealers to promote the slogan, ’A Picture Is Worth a Million Words." The dealers participating in the program are experiencing very robust sales, but PictureSharp analysts are concerned that the campaign is not successfully meeting its goals. Which of the following, if true, most justifies the concerns of the PictureSharp analysts that the campaign is not successful ？（）

A. The new PictureSharp slogan is a thinly veiled imitation of the better-known saying, "a picture is worth a thousand words."

B. PictureSharp is one of the leading manufacturers of digital cameras, which although generally more expensive than conventional film cameras, are considerably more versatile.

C. Many consumers who saw the commercials in this advertising campaign were concerned that they lacked the artistic skill to create a picture that would actually be worth "a million words."

D. Although almost all PictureSharp camera dealers participated in the advertising campaign by displaying promotional materials in their stores, some of them did not display or distribute all of the marketing materials that PictureSharp sent them.

E. All PictureSharp dealers also sell other brands of cameras, some of which are comparable to PictureSharp cameras in features and quality but significantly lower in price, allowing the dealers to charge a higher markup than for PictureSharp cameras.
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