九年级物理欧姆定律同步练习题及答案8.doc

九年级物理欧姆定律同步练习题及答案8 九年级物理欧姆定律同步练习题 一、选择题(33分) 1(小军同学想自制一个能调节灯泡亮暗的滑动变阻器(在选择电阻部分的材料时，有长 度相同的下列材料，你建议小军选择哪一种? ( ) A(不带绝缘皮的铜导线 B(塑料绳 C(细橡皮管 D(木工铅笔的粗铅笔芯 2(一段导体接在电压为9V的电源上时，通过导体的电流是1A，若将这段导体接在电压 为3V的电源上时，这段导体的电阻是( ) A( 9Ω B. 6Ω C .3Ω D.由9Ω变为3Ω 3(现有两个阻值不等的未知电阻R和R，为了分辨它们的阻值大小，几个同学分别设计12 了如图1所示的四种电路(图中小灯泡规格相同)，其中不可行的是:( ) 4(如图2电路，电源电压不变，开关S闭合后，灯L和 L都正常发光一段时间后，其中一12 盏灯突然熄灭，而电流表和电压表的示数都不变，出现这一现象的原因可能是( ) A(L短路 B(L短路 C(L断路 D. L断路 1212 5(小刚用图3所示电路探究“一段电路中电流跟电阻的关系”。在此实验过程中，当A、B两点间的电阻由5Ω更换为10Ω后，为了探究上述问题，他应该采取的唯一操作是 ( ) A.保持变阻器滑片不动 B.将变阻器滑片适当向左移动 C.将变阻器滑片适当向右移动 D.适当增加电池的节数 6(如图4所示，电源电压恒定不变，当s闭合后，滑动变阻器的滑片p向右移动的过程 中，下列说法正确的是 ( ) A.灯泡亮度不变，电压表示数变大 B.灯泡变亮，电压表示数变大 C.灯泡变暗，电压表示数变小 D.灯泡变暗，电压表示数变大 office, branch offices (jurisdiction), risk management, marketing management sector through supervision and inspection found problems, should be assigned the investigators are corrected in a timely manner. 27th the fifth chapter penalty under any of the following acts, then the relevant provisions to punish the investigators, according to the Bank. To constitute a crime shall be investigated for criminal responsibility: (A) on the business that are not involved in the investigation, issued a survey. (B) customer credit information are not thorough verification. (Iii) to participate in credit customer survey is not in place, customers and data is incomplete, untrue; he knows bear a counterfeited clients issuing credit. (D) does not provide for due diligence of credit business, pre-loan investigation form, concealing facts or providing false information or should be found in a normal investigation failed to discover the risk factors, lead to the review and approval policy errors, loan risk. (Five) on loan guarantees of survey not in place, not by provides on arrived, and pledge real for field verification, and assessment, and identification and registration, not according to provides on guarantor of guarantees qualification and guarantees capacity for survey verified, led to guarantees loa