南昌大学2018-2019大学物理期终试卷
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南昌大学 2011~2012 学年第一学期期末考试试卷试卷编号:6031 ( C )卷课程编号:J5502Z007 课程名称:普通物理(光学)考试形式:闭卷适用班级:10物理学、10应物姓名:学号:班级学院:专业:考试日期:题号一二三四五六七八九十总分累分人签名题分40 30 30 100得分考生注意事项:1、本试卷共5页,请查看试卷中是否有缺页或破损。
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一、填空题:(每空2分,共 40分)得分评阅人1、光强均为I o的两束相干光相遇而发生干涉时,在相遇区域内有可能出现的最大光强是__________。
2、当一束自然光在两种介质分界面处发生反射和折射时,若反射光为完全偏振光。
则折射光为_________偏振光,且反射光和折射光之间的夹角为___________。
3、光的偏振现象说明光波是_________波。
4、用纳光灯的纳黄光垂直照射光栅常数为d =3μm的衍射光栅,第五级谱线中纳黄光的(589.3nm)的角位置Φ5 = 。
5、在空气中用波长为λ的单色光进行双缝干涉实验时,观测到干涉条纹相邻明条纹的间距为1.33mm,当把实验装置放在水中时(水的折射率n=1.33),则相邻明条纹间距变为____________________。
6、若出射的同心光束是会聚的我们称之为__________。
7、把折射率为1.5 的玻璃片插入杨氏实验的一束光路中,光屏上原来第5 级亮条纹所在的位置为中央亮条纹,插入的玻璃片的厚度为_________。
(已知光波长为6×10-7m.)8、在双折射晶体内部,光在晶体内沿______传播时,e光和o光的传播速度相等。
9、若波长为6250 Ǻ的单色光垂直入射到一个每毫米有800条刻线的光栅上时,则该光栅的光栅常数为;第一级谱线的衍射角为。
10、人眼的明视距离cm。
11、物镜直径D=5cm的望远镜对可见光平均波长λ=550nm的最小分辨角是_______。
大学物理(下)试卷(A 卷)院系: 班级 :________ 姓名 :学号 :一、选择题(共 30 分,每题 3 分)EE1. 设有一 “无穷大” 平均带正电荷的平面.E ∝ x取 x (A) (B)轴垂直带电平面, 坐标原点在带电平面上,则其OOxx四周空间各点的电场强度 E 随距平面的地点坐标 x 变化的关系曲线为(规定场强方向沿x 轴正EE ∝ 1/|x|向为正、反之为负 ):E(C)(D)[]OxO x2. 如下图, 边长为 a 的等边三角形的三个极点上, 分别搁置着三个正的点电荷 q 、 2q 、 3q .若将另一正点电荷 Q 从无量远处移到三角形的中心 O 处,外力所作的功为:(A)2 3qQ . (B) 3qQ .0a 0 a3 3qQ(D)2 3qQ .2q(C). []2a0 a3. 一个静止的氢离子 (H + )在电场中被加快而获取的速率为一静止的氧离子中且经过同样的路径被加快所获速率的:(A) 2 倍. (B) 2 2 倍.(C) 4 倍.(D) 42 倍.[qaaOa3q(O +2) 在同一电场]4. 如下图,一带负电荷的金属球,外面齐心地罩一不带电的金属球壳,则在球壳中一点 P 处的场强盛小与电势 (设无量远处为电势零点) 分别为:(A) E=0,U>0. (B) E=0,U<0 . P(C)E=0,U=0.(D)E>0,U< 0 .[]5. C 1 和 C 2 两空气电容器并联此后接电源充电.在电源保持联接C 1C 2的状况下,在 C 1 中插入一电介质板,如下图 , 则(A) C 1 极板上电荷增添, C 2 极板上电荷减少.(B) C 1 极板上电荷减少, C 2 极板上电荷增添.(C) C 1 极板上电荷增添, C 2 极板上电荷不变.(D) C 1 极板上电荷减少, C 2 极板上电荷不变.[ ]6. 对位移电流,有下述四种说法,请指出哪一种说法正确.(A) 位移电流是指变化电场.(B) 位移电流是由线性变化磁场产生的.(C) 位移电流的热效应听从焦耳─楞次定律. (D) 位移电流的磁效应不听从安培环路定理.[ ]7. 有以下几种说法:(1) 全部惯性系对物理基本规律都是等价的.(2) 在真空中,光的速度与光的频次、光源的运动状态没关.(3) 在任何惯性系中,光在真空中沿任何方向的流传速率都同样.若问此中哪些说法是正确的 , 答案是(A)只有 (1) 、 (2)是正确的. (B) 只有 (1) 、 (3)是正确的.(C) 只有 (2) 、 (3)是正确的.(D)三种说法都是正确的.[ ]8. 在康普顿散射中,假如设反冲电子的速度为光速的 60%,则因散射使电子获取的能量是其静止能量的(A) 2 倍.(B) 1.5 倍.(C) 0.5 倍.(D) 0.25 倍.[ ]9. 已知粒子处于宽度为 a 的一维无穷深势阱中运动的波函数为n (x)2 sin n x ,n = 1, 2, 3,a a则当 n = 1 时,在 x 1 = a/4 →x 2 = 3a/4 区间找到粒子的概率为(A) 0.091 . (B) 0.182 .(C) 1. . (D) 0.818 . [ ]10. 氢原子中处于3d 量子态的电子,描绘其量子态的四个量子数(n ,l ,m l ,m s )可能取的值为(A) (3, 0,1,1(B)(1,1, 1, 1) .).221).(D)(3, 2, 0,1 [](C) (2, 1,2,).22二、填空题(共30 分)11.(此题 3 分)一个带电荷 q 、半径为 R 的金属球壳,壳内是真空,壳外是介电常量为的无穷大各向同性平均电介质,则此球壳的电势U =________________ .12. (此题 3 分)R 3R 1I I有一实心同轴电缆,其尺寸如下图,它的内外两导体中的电流均为 I ,且在横截面上平均散布,但两者电流的流向正相反, 则在 R 2r < R 1 处磁感强度大小为 ________________ .13. (此题 3 分)磁场中某点处的磁感强度为B 0.40i 0.20 j (SI) ,一电子以速度106 i 1.0 10 6 j (SI) 通 过 该 点 , 则 作 用 于 该 电 子 上 的 磁 场 力 F 为__________________ . (基本电荷 e=1.6 ×10 19C)14.(此题 6 分,每空 3 分)四根辐条的金属轮子在平均磁场B 中转动,转轴与 B 平行,轮R子和辐条都是导体,辐条长为OR ,轮子转速为 n ,则轮子中心 O 与轮边沿 b 之间的感觉电动势为______________,电势最高点是在Bb______________处.O15. (此题 3 分)有一根无穷长直导线绝缘地紧贴在矩形线圈的中心轴 OO ′上,则直导线与矩形线圈间的互感系数为_________________ .O ′16.(此题 3 分)真空中两只长直螺线管 1 和 2,长度相等, 单层密绕匝数同样, 直径之比 d 1 / d 2 =1/4 .当它们通以同样电流时,两螺线管储存的磁能之比为W 1 / W 2=___________ . 17. (此题 3 分)静止时边长为50 cm 的立方体,当它沿着与它的一个棱边平行的方向相对于地面以匀速度-1 运动时,在地面上测得它的体积是____________.× 108 m · s 18. (此题 3 分)以波长为 = 0.207 m 的紫外光照耀金属钯表面产生光电效应,已知钯的红限频次×1015 赫兹,则其制止电压 |U a | =_______________________V .(普朗克常量× 10- 34 J ·s ,基本电荷 × 10- 19 C)19. (此题 3 分)x 与 x + x 之间, x =0.5 ? ,则电子动量 x 重量的不确立量近似假如电子被限制在界限地为 ________________kg ·m / s . (取 x · p ≥h ,普朗克常量 × 10-34 J · s)三、计算题(共 40 分)20. (此题 10 分)散布在半径为 r 1= 10 cm 和 r2= 20 cm 的两个齐心球面上.设无电荷以同样的面密度限远处电势为零,球心处的电势为U0=300 V .(1)求电荷面密度.(2)若要使球心处的电势也为零,外球面上电荷面密度应为多少,与本来的电荷相差多少?[电容率 0× 10-1222=C/(N · m ) ]21. (此题 10 分)已知载流圆线圈中心处的磁感强度为B0,此圆线圈的磁矩与一边长为 a 经过电流为 I 的正方形线圈的磁矩之比为2∶1,求载流圆线圈的半径.22.(此题 10 分)如下图,一磁感觉强度为 B 的平均磁场充满在半径为R 的圆柱形R体内,有一长为 l 的金属棒放在磁场中,假如 B 正在以速率 dB/dt 增添,ob 试求棒两头的电动势的大小,并确立其方向。
南昌大学大学物理期末考试《大学物理》(下)期末统考试题(A卷)说明 1考试答案必须写在答题纸上,否那么无效。
请把答题纸撕下。
一、选择题(30分,每题3分)1.一质点作简谐振动,振动方程x=Acos(ωt+φ),当时间t=T/4(T为周期)时,质点的速度为:(A) -Aωsinφ;(B) Aωsinφ; (C) -Aωcosφ; (D)Aωcosφ参考解:v =dx/dt = -Aωsin(ωt+φ)vtT/4Asin(2TT)Acos, ∴选(C) 42.一弹簧振子作简谐振动,当其偏离平衡位置的位移的大小为振幅的1/4时,其动能为振动总能量的(A) 7/6 (B) 9/16(C) 11/16 (D)13/16(E) 15/16 参考解:3.一平面简谐波在弹性媒质中传播,在媒质质元从平衡位置运1121A2mv2115 kAk(),2116kA2kA∴选(E)动到最大位移处的过程中:(A)它的动能转换成势能.(B) 它的势能转换成动能.(C) 它从相邻的一段质元获得能量其能量逐渐增大.(D) 它把自己的能量传给相邻的一段质元,其能量逐渐减小.参考解:这里的条件是“平面简谐波在弹性媒质中传播”。
由于弹性媒质的质元在平衡位置时的形变最大,所以势能动能最大,这时动能也最大;由于弹性媒质的质元在最大位移处时形变最小,所以势能也最小,这时动能也最小。
质元的机械能由最大变到最小的过程中,同时也把该机械能传给相邻的一段质元。
∴选(D)4.如下图,折射率为n2、厚度为e的透明介质薄膜的上方和下方的透明介质的折射率分别为n1和n3,n1<n2<n3.假设用波长为的单色平行光垂直入射到该薄膜上,那么从薄膜上、下两外表反射的光束①与②的光程差是(A) 2n2 e.(B) 2n2 e- / 2 .(C) 2n2 e-.(D) 2n2 e- / (2n2). n3 参考解:半波损失现象发生在波由波疏媒质到波密媒质的界面的反射现象中。
本文部分内容来自网络整理,本司不为其真实性负责,如有异议或侵权请及时联系,本司将立即删除!== 本文为word格式,下载后可方便编辑和修改! ==大学物理试题及答案篇一:大学物理试题及答案21.一质点沿x轴运动的规律是x?t?4t?5(SI制),则前三秒内它的(A) 位移和路程都是3m; (B) 位移和路程都是-3m;(C) 位移是-3m,路程是3m; (D) 位移是-3m,路程是5m;2.f?v?为麦克斯韦速率分布函数,则f?v?dv表示(A) 速率v附近,dv区间内的分子数; (B) 单位体积内速率在v~v+dv区间内的分子数;(C) 速率v附近,dv区间分子数占总分子数的比率; (D) 单位体积内速率在v附近单位区间内的分子数;3.一质点在力的作用下在X轴上作直线运动,力F?3x2,式中F和x的单位分别为牛顿和米。
则质点从x?1m处运动到x?2m的过程中,该力所作的功为:(A)42J;(B)21J;(C)7J;(D)3J;4.已知某简谐运动的振动曲线如图所示,则此简谐运动的运动方程(x的单位为cm,t的单位为s)为2??2(A)x?2cos??t???;(B)3??32??2x?2cos??t???; 3??32??4(C)x?2cos??t???;(D)3??32??4x?2cos??t???; 3??35.一理想卡诺热机的效率??40%,完成一次循环对外作功A?400J,则每次循环向外界放出的热量为:(A)160J;(B)240J;(C)400J;(D)600J;6. 关于横波和纵波下面说法正确的是(A)质点振动方向与波的传播方向平行的波是横波,质点振动方向与波的传播方向垂直的波是纵波;(B)质点振动方向与波的传播方向平行的波是纵波,质点振动方向与波的传播方向垂直的波是横波;(C)纵波的外形特征是有波峰和波谷;(D)横波在固体、液体和气体中均能传播;7. 用水平力FN把一个物体压着靠在粗糙的竖直墙面上保持静止。
试卷编号:( B )卷南昌大学2018~2019学年第二学期期中考试试卷大学英语C班课程编号:T5103I001 课程名称:大学英语考试形式:闭卷适用班级:2018级大学英语C班姓名:学号:班级:学院:专业:英语班级: 考试日期:2019年4月18日考生注意事项:1.本试卷共8页,请查看试卷中是否有缺页或破损。
如有立即举手报告以便更换;2.本次考试分A,B两种试卷,请看清自己的试题册上面的试卷类型,用铅笔在相应的字母上划线;3. 答题卡上的准考证号用本人学号,填写后请用铅笔分别在下面对应的数字上划线;4. 考试结束后回收答题卡,试卷册可由学生带走;Part I Reading Comprehension(每题3分,共45分)Directions: There are 3 reading passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the centre.Passage OneQuestions 1 to 5 are based on the following passage:Plastics are materials which are softened by heat and set into lasting from when shaped in a mold. Some are natural; some are semi-synthetic, the result of chemical action on a natural substance; some are synthetic, built up from the constituents of oil or coal. All are based on the chemistry of carbon, with its capacity for forming chains. The molecules that compose them (monomers) link together in the setting or curing (固化) process to form chains (polymers), which give plastics their flexible strength. Some plastics retain their ability to be softened and reshaped; like wax, they are thermoplastic. Others set permanently in the shapes they are given by heat and pressure; like eggs, they are thermosetting.From industrial beginnings in the nineteenth century, plastics have struggled through a hundred and twenty years of glory, failure, disrepute (坏名声) and suspicion on the slow road to public acceptance. Now, at last, one can positively say that plastics are appreciated and enjoyed for what they are; that they make modern life richer, more comfortable and convenient and also more funny. Plastics are warm materials, sympathetic to the human touch, and their transformation into things that come into contact with human beings is entirely appropriate.The fact that there plastic antiques comes as a shock to most people. How can a material that seems so essential in the twentieth century, and one that is so much associated with cheap disposable products, have a history at all? It is a young technology, and a great part of the fun of collecting plastics is that beautiful pieces of historical interest can still found very cheaply.1. Which of the following is the best title for the passage?A) The development of Plastics as a Modern MaterialB) How Plastics Are MaterialC) The Importance of Plastics in the Nineteenth CenturyD) Why people Are Suspicious of Plastics2. Which of the following is necessary to create any type of plastics?A) Coal.B) Eggs.C) Oil.D) Carbon.3. According to the author, for approximately how many years have plastics existed?A) 160.B)120.C)140.D) 100.4. What historical information does the second paragraph give about plastics?A)They originated primarily as road-surfacing materials.B) The earliest types were soft and did not last very long.C)Their popularity was at its height at the time of the Industrial Revolution.D) They have come into general use very gradually.5. Why does the author mention antiques in the third paragraph?A) Young collectors prefer real antiques to plastic objects.B) Dealers use inexpensive plastic parts to repair valuable antiques.C) Some plastic objects are now considered antiques.D) Plastics replicas (复制品) of valuable antiques are relatively common.Passage TwoQuestions 6 to 10 are based on the following passage:When memory began for me, my grandfather was past sixty -- a great tall man with thick hair becoming gray. He had black eyes and a straight nose which ended in a slightly flattened tip. Once he explained seriously to me that he got that flattened tip as a small child when he fell down and stepped on his nose. The little marks of laughter at the corners of his eyes were the product of a kindly and humorous nature. The years of work which had bent his shoulders had never dulled his humor nor his love of a joke. Everywhere he went, ''Gramp'' made friends easily. At the end of half an hour you felt you had known him all your life. I soon learned that he hated to give orders, but that when he had to, he tried to make his orders sound like suggestions.One July morning, as he was leaving to go to the cornfield, he said, ''Edwin, you can pick up the potatoes in the field today if you want to do that.'' Then he drove away with his horses.The day passed, and I did not have any desire to pick up potatoes. Evening came and the potatoes were still in the field. Gramp, dusty and tired, led the horses to get their drink.''How many bags of potatoes were there?'' Gramp inquired.''I don't know.''''How many potatoes did you pick up?''''I didn't pick any.''''Not any! Why not?''''You said I could pick them up if I wanted to. You didn't say I had to.''In the next few minutes I learned a lesson I would not forget: when Gramp said I could if I wanted to, he meant that I should want to.My grandmother (''Gram'') worked hard all day, washing clothes, cleaning the house, making butter, and even working in the field when help was scarce. In the evening, though, she was not too tired to read books from the community library. For more than forty years Gram read aloud to Gramp almost every evening. In this way she and Gramp learned about all the great battles of history and became familiar with the works of great authors and the lives of famous men.Gram hated cruelty and injustice. The injustices of history, even those of a thousand years before, angered her as much as the injustices of her own day.She also had a deep love of beauty. When she was almost seventy-five, and had gone to live with one of her daughters, she spent a delightful morning washing dishes because, as she said, the beautiful patterns on the dishes gave her pleasure. The birds, the flowers, the clouds -- all that was beautiful around her -- pleased her. She was like the father of the French painter, Millet, who used to gather grass and show it to his son, saying, ''See how beautiful this is!''In a pioneer society it is the harder qualities of mind and character that are of value. The softer virtues are considered unnecessary. Men and women struggling daily to earn a living are unable, even for a moment, to forget the business of preserving their lives. Only unusual people, like my grandparents, manage to keep the softer qualities in a world of daily struggle.Such were the two people with whom I spent the months from June to September in the wonderful days of summer and youth.6. We know that Grandpa's nose _________.A) was flattened because it had been stepped onB) was not flat when he was a boyC) was both straight and broadD) was straight but its tip was a bit flat7. We learn from the passage that Grandpa _________.A) was friendly and humorousB) liked making suggestionsC) loved to give ordersD) was a serious and strict person8. When Grandpa told the writer to pick up potatoes if he wanted to do that, he meant that _________.A) he could do it if he wanted toB) he did not really have to do soC) he could do it anytime he was readyD) he had to do it9. The writer describes his Grandma as _________.A) a woman who complained about the injustices of lifeB) a very obedient housewifeC) someone who could find beauty in lifeD) a woman who loved Millet's paintings10. According to the passage, in the days of the writer's grandparents _________.A) most people understood how to appreciate the beautiful thingsB) in life it was difficult for people to keep the "soft qualities" of mind and characterC) only ordinary people managed to appreciate the beauty of natureD) it was the "soft virtues" that were thought to be very importantPassage ThreeQuestions 11 to 15 are based on the following passage:Like a lot of black kids, we never would have made it without our Momma. When there was no fatback to go with the beans, no socks to go with the shoes, no hope to go with tomorrow, she’s smile and say: “We ain’t poor, we’re just broke.”Poor is a state of mind you never grow out of, but being broke is just a temporary condition. She always has a big smile, even when her legs and feet swelled from high blood pressure and she collapsed across the table with diabetes. You have to smile twenty-four hours a day, Momma would say. If you walk through life showing the aggravation you’ve gone through, people will feel sorry for you, and they’ll never respect you.So you laugh, so you smile. Once a month the big gray relief truck would poll up in front of our house and Momma would flash that big smile and stretch out her hands: “Who else you know in this neighborhood gets this kind of service?”And we could all feel proud when the neighbors, folks who weren’t on relief, folks who had Daddies in their houses, would come by the back porch fro some of those hundred pounds of potatoes, for some sugar and flour and salty fish. We’d stand out there on the back porch and hand out the food like we were in charge of helping poor people, and then we’d take the food they brought us in return.And Momma came home one hot summer day and found we’d been evicted, thrown out into the streetcar zone with all our orange crate chairs and secondhand lamps. She flashed that big smile and dried our tears and bought some penny Kool-Aid. We stood out there and sold drinks to thirsty people coming off the streetcar, and we thought nobody knew we were kicked out—figured they thought we wanted to be there. And Momma went off to talk the landlord into letting us back in on credit.But I wonder about my Momma sometimes, and all the other black mothers who got up at 6 a.m. to go to the white man’s house with sacks over their shoes because it was so wet and cold. I wonder how they made it. They worked very hard for the man, they made his breakfast and they scrubbed his floors and they diapered his babies. They didn’t have to much time for us.I wonder about my Momma, who walked out of a white woman’s clean house at midnight and came back to her own where the lights had been out for three months, and the pipes were frozen and the wind came in through the cracks. She’d have to make deals with the rats: ;eave some food out for them so they would n’t gnaw on the doors or bite the babies. The roaches, they were just live part of the family.I wonder how she felt telling those white kids she took care of to brush their teeth after they ate, to wash their hands after they peed. She could never tell her own kids because there was n’t soap or water backhome.I wonder how my Momma felt when we came home from school with a list of vitamins and pills and cod liver oil the school nurse said we had to have. Momma would cry all night, and then go out and spend most of the rent money for pills. A week later, the white man would come for his eighteen dollars rent and Momma would plead with him to wait until tomorrow. She had lost her pocketbook. The relief check was coming. The white fold had some money for her. Tomorrow, I’d be hiding in the coal closet because there was only supposed to be two kids in the flat, and I could hear the rent man curse my Momma and call her a liar.I wonder how my Momma stayed so good and beautiful in her soul when she worked seven days a week on swollen legs and feel, how she kept teaching us to smile and laugh when the house was dark and cold and she never knew when one of her hungry kids was going to ask about Daddy.I wonder how she kept from teaching us hate when the social worker cam around. She was a nasty bitch with a pinched face who said, “We have reason to suspect you are working, Miss Gregory, and you can be sure I’m going to check on you. We don’t stand for welfare cheaters.”Momma, a welfare cheater. A criminal who couldn’t stand to see her kids go hungry, or grow up in slums and end up mugging people in dark corners. I guess the system didn’t want her to get off relief, the way it kept sending social workers around to be sure Momma wasn’t trying to make things better.I remember how that social worker would poke around the house, wrinkling her nose at the coal dust on the chilly linoleum floor, shaking her head at the buds crawling over the dirty dishes in the sink. My Momma would have to stand there and make like she was too lazy to keep her own house clean. She could never let on that she spent all day cleaning another woman’s house for two dollars and carfare. She would have to follow that nasty bitch around those drafty three rooms, keeping her fingers crossed that the telephone hidden in the closet wouldn’t ring. Welfare cases weren’t supposed to have telephone.But Momma figured that some day the Gregory kids were going to get off North Taylor Street and into a world where they would have to compete with kids who grew up with telephones in their houses. She didn’t want us to be at a disadvantage. She couldn’t explain that to social worker. And she couldn’t explain that while she was out spoon-feeding somebody else’s kids, she was worrying about her own kids, that she could rest her mind by picking up the telephone and calling us-to find out if we had bread for our baloney or baloney for our bread, to see if any of us and gotten run over by the streetcar while we played in the gutter, to make sure the house hadn’t burnt down from the papers and magazines we stuffed in the stove when the coal ran out.11. From the passage, we can learn that the author’s mother was _____.A) cynical and lazyB) optimistic and hard-workingC) critical and passiveD) pessimistic and intolerant12. Implied but not stated about the author’s family is that ____.A) the family lived in a rented flatB) the father didn’t live with themC) the family was actually very richD) the author’s mother got divorced several times13. Why did the author’s mother smile and say those words when the big relief truck came?A) Because she was greeting the truck driver.B) Because she was trying to relieve her nervousness.C) Because she did not want her children to feel inferior to their neighbors.D) Because she was proud in accepting this kind of service.14. When the family were driven out of the rented flat, the author’s mother ____.A) cursed her bad luck and gave up in despairB) was indignant and criticized her children severely for disobeying herC) was frantic and looked for a flat everywhereD) appeared calm and managed to solve the problem by persuading the landlord to let them back15. Why did the author have to hide in the coal closet when the landlord came to collect rent?A) Because the author wanted to play games with the landlord.B) Because there was no room for the author to stay in.C) Because the author wanted to frighten the landlord away.D) Because the landlord allowed only two children in the flat.Part II Vocabulary and Structure (每题1.5分,共30分)Directions: There are 20 incomplete sentences in this part. For each sentence there are four choices marked A), B), C) and D). Choose ONE answer that completed the sentence. Then mark the corresponding letter on the Answer Sheet with a single line through the center.16. If I work hard, I think I can _________ my goal of getting 6 A’s at the end of the semester.A) manage B) summarize C) accomplish D) apply17. Their investment turned out to be a failure and the manager was accused of _________ his duties.A) inserting B) investigating C) distracting D) neglecting18. He could be ________ about everything else in the world, but not about Manet, his loving child.A) extreme B) essential C) visual D) critical19. If you want to be a good speaker, you must _________ your own style of writing.A) contrast B) continue C) exaggerate D) evolve20. The school will give_________ to English and computer studies.A) principle B) priority C) principal D) proof21. I chose my words carefully in order to avoid _________ anyone.A) evolving B) emerging C) embarrassing D) exaggerating22. They claimed that they knew how to play the system and __________ it.A) hold to B) blend into C) make up for D) get away with23. These college students _______ being praised because of saving the drowned child.A) dessert B) desert C) deserve D) assert24. His thoughts were _________ from the subject by the arrival of his friends.A) attracted B) suffered C) distracted D) related25. The young man knew __________ that he should have married his first love Emily.A) in retrospect B) on occasion C) in due course D) in the least26. Witnesses showed the police the exact __________ of the accident.A) proof B) treatment C) location D) contrast27. Highly trained staff are well __________ to give practical advice to students when they select courses.A) stretched B) interrupted C) disturbed D) qualified28. Vivid memories came flooding back of the __________, romantic sophomore year.A) enormous B) glorious C)delicious D) conscientious29. The international community is ready to work __________ against terrorism.A) in unison B) from all accounts C) on their own D) to the point30. Though online bookstores usually offer ________, don’t expect to save much.A) priorities B) exceptions C) discounts D) rewards31. The police department attempted to ____________ the list of suspects.A) narrow down B) take in C) come over D) hand down32. New employees who __________ in the last six weeks have not been tested.A) came aboard B) laid down C) opened up D) carried on33. After __________ all her ready excuses, she could think of nothing else to say.A) swallowing B) exhausting C) consuming D) inventing34. The college has a few ways to assess the quality of education __________.A) overall B) emotionally C) relevantly D) gloriously35. Members of the club __________ controversial issues such as religion.A) hold to B) catch up with C) steer clear of D) come up toPart III Cloze (第一篇每空1.5分;第二篇每空1分,共25分)Directions:There are two passages in this part. There are 20 blanks in the following passages. For each blank there are four choices marked A), B), C) and D). You should choose the ONE that best fits into the passage. Then mark the corresponding letter on the Answer Sheet with a single line through the centre.Passage 1With a few exceptions my Chinese colleagues ___36__the same attitude as the staff at the Jinling Hotel. Since adults know how to place the key in the key slot, which is the ___37___ purpose of approaching the slot, and since the child is neither old enough nor clever enough to realize ___38___ the action on his own, what possible gain is achieved by having him struggle? He may well get ___39__and angry-----certainly not a desirable outcome. Why not show him what to do? He will be happy, he will learn how to accomplish the task sooner, and then he can ___40__to more complex activities, like opening the door or asking for the key---both of which accomplishments can (and should) in due course be modeled for him as well.We listened to such explanations ___41___and explained that, first of all, we did not much care whether Benjamin succeeded in inserting the key into the slot. He was having a good time and was exploring, two activities that did matter to us. But the critical point was that, in the___42__, we were trying to teach Benjamin that one can solve a problem effectively by oneself. Such __43__ is a principal value of child rearing in middle-class American. So long as the child is shown exactly how to do something ------ whether it __44__ a key in a key slot , drawing a hen or making up for a misdeed---he is less likely to figure out himself how to accomplish such a task. And, more generally, he is less __45__ to view life------ as Americans do ------ as a series of situations in which one has to learn to think for oneself, to solve problems on one’s own and even to discover new problems for which creative solutions are wanted.36. A) to be displayed B) displayed C) displaying D) to displayed37. A) ultimate B) relevant C) due D) remote38. A) desire B) desiring C) desired D) desirable39. A) frustrated B) confused C) stunned D) involved40. A) proceed B) decide C) select D) solve41. A) reluctantly B) certainly C) continually D) sympathetically42. A) following B) project C) course D) process43. A) self-reliance B) self-esteem C) self-support D) self-confidence44. A) is placed B) was placed C) be placed D) be placing45. A) unlikely B) likely C) willingly D) unwillinglyPassage 2Once he campaigned his way to the presidency, Carter occasionally managed ___46___ slip in a few hours at the carpenter's shed at Camp David, because, in his ___47___, "What we need in our lives is a stock of factors that never change. I think that skill with ___48___ own hands -- whether it's tilling the soil, building a house, making a piece of furniture, playing ___49___ violin or painting a painting -- is something that doesn't change with the ups and downs of life. And for me, going back to the earth or going back to the woodshop have always been opportunities to___50___ my basic skills. No matter if I was ___51___ in writing a book, ___52___ a political campaign, teaching at Emory University or dealing with international ___53___, I could always go back -- at least for a few hours at a time -- to the woodshop. That's meant an ___54___ lot to me. It's a kind of ___55___, but it's also a steadying force in my life -- a total rest for my mind.46. A) in B) to C) on D) for47. A) idea B) sense C) opinion D) mind48. A) his B) one’s C) their D) our49. A) an B) the C) / D) a50. A) practice B) accomplish C) prove D) reinforce51. A) involved B) involving C) involves D) involve52. A) conducting B) going C) protesting D) carrying53. A) incidents B) stories C) events D) affairs54. A) awed B) awful C) awesome D) awe55. A) therapy B) treatment C) medicine D) cure。
南昌大学第二届大学物理竞赛试卷填空(每题3分)1. 在x 轴上作直线运动的质点,已知其初速度为v 0,初位置为x 0,加速度a=At 2+B(A 、B 为常数),则t 时刻质点的速度v= ;运动方程为 。
2.质量为m 的子弹,水平射入质量为M 、置于光滑水平面上的沙箱,子弹在沙箱中前进距离l 而停止,同时沙箱向前运动的距离为s ,此后子弹与沙箱一起以共同速度v 匀速运动,则子弹受到的平均阻力F=__________________。
3.如图所示,质量为M ,长度为L 的刚体匀质细杆,能绕首过其端点o 的水平轴无摩擦地在竖直平面上摆动。
今让此杆从水平静止状态自由地摆下,当细杆摆到图中所示θ角位置时,它的转动角速度ω=__________,转动角加速度β=__________;当θ=900时,转轴为细杆提供的支持力N =__________。
4.质量为M ,长度为L 的匀质链条,挂在光滑水平细杆上,若链条因扰动而下滑,则当链条的一端刚脱离细杆的瞬间,链条速度大小为___________________。
5.将一静止质量为M o 的电子从静止加速到0.8c (c 为真空中光速)的速度,加速器对电子作功是__________。
6.有两个半径分别为5cm 和8cm 的薄铜球壳同心放置,已知内球壳的电势为2700V 。
外球壳带电量为8³10-9C 。
现用导线把两球壳联接在一起,则内球壳电势为__________V 。
7.半经为R 的圆片均匀带电,电荷面密度为σ。
其以角速度ω绕通过圆片中心且垂直圆平面的轴旋转,旋转圆片的磁矩m P的大小为____________。
8.用长为l 的细金属丝OP 和绝缘摆球P 构成一个圆锥摆。
P 作水平匀速圆周运动时金属丝与竖直线的夹角为θ,如图所示,其中o 为悬挂点。
设有讨论的空间范围内有水平方向的匀强磁场,磁感应强度为B。
在摆球P 的运动过程中,金属丝上P 点与O 点间的最小电势差为__________。
南昌大学 2005~2006学年第二学期期末考试试卷试卷编号: ( A )课程编号: T55020001--03 课程名称: 大学物理 考试形式: 闭卷 适用班级: 理工05级(Ⅰ)、〔Ⅱ〕、〔Ⅲ〕姓名: 学号: 学院: 专业: 班级: 考试日期:06年6月题号 一 二 三 四五六总分 累分人 签名题分 30 22 48 100 得分本试卷共6页,得分 评阅人、质点在力y F 22== ,= 。
其运动学方程为x = 8 由0至4s 的时间OR △QABE 0E 0/3E 0/3第3题图二、 选择题(每题 2 分,共 22分)得分 评阅人1、一光滑的内外表半径为10 cm 的半球形碗,以匀角速度ω绕其对称OC 旋转.放在碗内外表上的一个小球P 相对于碗静止,其位置高于碗底4 cm ,则由此可推知碗旋转的角速度约为 (A) 10 rad/s . (B) 13 rad/s .(C) 17 rad/s (D) 18 rad/s . [ ]ωPCOAMBF第1题图 第2题图2、如下图,A 、B 为两个相同的绕着轻绳的定滑轮.A 滑轮挂一质量为M 的物体,B 滑轮受拉力F ,而且F =Mg .设A 、B 两滑轮的角加速度分别为βA 和βB ,不计滑轮轴的摩擦,则有 (A) βA =βB . (B) βA >βB .(C) βA <βB . (D) 开始时βA =βB ,以后βA <βB . [ ] 3、 假设卫星围绕地球中心作圆周运动,则在运动过程中,卫星对地球中心的 (A) 角动量守恒,动能也守恒. (B) 角动量守恒,动能不守恒. (C) 角动量不守恒,动能守恒. (D) 角动量不守恒,动量也不守恒.(E) 角动量守恒,动量也守恒. [ ] 4、如下图,一匀质细杆可绕通过上端与杆垂直的水平光滑固定轴O 旋转,初始状态为静止悬挂.现有一个小球自左方水平打击细杆.设小球与细杆之间为非弹性碰撞,则在碰撞过程中对细杆与小球这一系统(A) 只有机械能守恒. (B) 只有动量守恒. (C) 只有对转轴O 的角动量守恒.(D) 机械能、动量和角动量均守恒. [ ]OEO r(B) E ∝1/r 2RE O r(A) E ∝1/r 2 REOr(C) E ∝1/r 2REOr(D) E ∝1/r 2第4题图 第5题图5、半径为R 的均匀带电球面的静电场中各点的电场强度的大小E 与距球心的距离r 之间的关系曲线为:[ B ]6、把戏滑冰运发动绕通过自身的竖直轴转动,开始时两臂伸开,转动惯量为J 0,角速度为ω0.然后她将两臂收回,使转动惯量减少为31J 0.这时运发动转动的角速度变为 (A)31ω0. (B) ()3/1 ω0. Jw(C) 3 ω0. (D) 3 ω0. [ ]R OUrU ∝1/r(A) R OUrU ∝1/r(B) R OUrU ∝1/r(C)R OUrU ∝1/r 2(D)ROUr U ∝1/r 2(E)第7题图7、半径为R 的均匀带电球面,总电荷为Q .设无穷远处电势为零,则该带电体所产生的电场的电势U ,随离球心的距离r 变化的分布曲线为[ ]8、有两个大小不相同的金属球,大球直径是小球的两倍,大球带电,小球不带电,两者相距很远.今用细长导线将两者相连,在忽略导线的影响下,大球与小球的带电之比为: (A) 2. (B) 1.(C) 1/2. (D) 0. [ ] 9、在点电荷+q 的电场中,假设取图中P 点处为电势零点 , 则M 点的电势为(A)a q 04επ. (B) a q08επ.(C) a q 04επ-. (D) aq08επ-. [ ]aa+qPMⅠⅡⅢⅣ第9题图 第10题图10、图中,六根无限长导线互相绝缘,通过电流均为I ,地域Ⅰ、Ⅱ、Ⅲ、Ⅳ均为相等的正方形,哪一个地域指向纸内的磁通量最大?(A) Ⅰ地域. (B) Ⅱ地域. (C) Ⅲ地域. (D) Ⅳ地域.(E) 最大不止一个. [ ] 11、 有以下几种说法: (1) 全部惯性系对物理根本规律都是等价的. (2) 在真空中,光的速度与光的频率、光源的运动状态无关.(3) 在任何惯性系中,光在真空中沿任何方向的传播速率都相同.假设问其中哪些说法是正确的, 答案是(A) 只有(1)、(2)是正确的. (B) 只有(1)、(3)是正确的. (C) 只有(2)、(3)是正确的. (D) 三种说法都是正确的. [ ]三、计算题(共48分)得分 评阅人1、一物体悬挂在弹簧上作竖直振动,其加速度为-=a ky ,式中k 为常量,y 是以平衡位置为原点所测得的坐标. 假定振动的物体在坐标y 0处的速度为v 0,试求速度v 与坐标y 的函数关系式.〔此题7分〕解: yt y y t a d d d d d d d d vvv v === 又 -=a ky ∴ -k =y v d v / d y 3分⎰⎰+=-=-C ky y ky 222121 , d d v v v 3分=y y 0 ,=v v 0 则 20202121ky C --=v )(220202y y k -+=v v 1分2、质量m = kg 的匀质圆盘,可以绕通过其中心且垂直盘面的水平光滑固定轴转动,对轴的转动惯量J =221mr (r 为盘的半径).圆盘边缘绕有绳子,绳子下端挂一质量m 1=1.0kg 的物体,如下图.起初在圆盘上加一恒力矩使物体以速率v 0= m/s 匀速上升,如撤去所加力矩,问经历多少时间圆盘开始作反方向转动.〔此题7分〕m 1m ,r3、如下图,一长为10 cm 的均匀带正电细杆,其电荷为×10-8 C ,试求在杆的延长线上距杆的端点5 cm 处的P 点的电场强度.(41επ=9×109 N ·m 2/C 2 )〔此题8分〕P 10 cm5 cm4、一链条总长为 l ,质量为m ,放在桌面上,并使其下垂,下垂一端的长度为a ,设链条与桌面之间的滑动摩擦系数为μ,令链条由静止开始运动,则 到链条离开桌面的过程中,摩擦力对链条作了多少功?〔此题8分〕5、半径为R 的半圆线圈ACD 通有电流I 2,置于电流为I 1的无限长直线电流的磁场中,直线电流I 1恰过半圆的直径,两导线相互绝缘.求半圆线圈受到长直线电流I 1的磁力. 〔此题10分〕I 2I 1A DC6、如下图,有一根长直导线,载有直流电流I ,近旁有一个两条对边与它平行并与它共面的矩形线圈,以匀速度v沿垂直于导线的方向离开导线.设t =0时,线圈位于图示位置,求(1) 在任意时刻t 通过矩形线圈的磁通量 .(2) 在图示位置时矩形线圈中的电动势. 〔此题8分〕Ia bv l2005~2006-2期末考试A 试卷评分参考标准一、1、0 ; 18J 2、 0 m ;16 m 3、()40216/R S Q ε∆π 由圆心O 点指向△S4、 -2ε0E 0 / 3 ; 4ε0E 0 / 35、 q / (6πε0R )6、 1∶17、 1.2×103 T8、×1089、狭义相对论的两条原理说的是相对性原理和光速不变原理 10、ADCBA 绕向 二、B 、C 、A 、C 、B 、D 、A 、A 、D 、B 、D 、三、1、解: yt y y t a d d d d d d d d vvv v === 又 -=a ky ∴ -k =y v d v / d y 3分⎰⎰+=-=-C ky y ky 222121 , d d v v v 3分=y y 0 ,=v v 0 则 20202121ky C --=v )(220202y y k -+=v v 1分 2、撤去外加力矩后受力分析如下图.m 1g -T = m 1a 1分Tr =J β 2分a =r β 1分 a = m 1gr / ( m 1r + J / r ) 代入J =221mr , a =mm gm 2111+= 6.32 ms -2 1分 ∵ v 0-at =0 1分 ∴ t =v 0 / a =0.095 s 1分3、解: 设P 点在杆的右边,选取杆的左端为坐标原点O ,x 轴沿杆的方向,如图,并设杆的长度为L .P 点离杆的端点距离为d .在x 处取一电荷元d q =(q /L )d x ,它在P 点产生场强()()20204d 4d d x d L L xq x d L q E -+π=-+π=εε 3分 P 点处的总场强为()()d L d qx d L x L q E L +π=-+π=⎰00204d 4εε 3分 代入题目所给数据,得E =×104 N/m 1分E的方向沿x 轴正向. 1分4、某一时刻的摩擦力为x l mg f )(-=μ, 4分 摩擦力作功为:2)(2)(d )(a l lmg dx x l l mg x f A l a l a f --=--=-=⎰⎰μμ 4分5、解:长直导线在周围空间产生的磁场分布为 )2/(10r I B π=μ取xOy 坐标系如图,则在半圆线圈所在处各点产生的磁感强度大小为:θμsin 210R I B π=, 方向垂直纸面向里, 2分精品文档式中θ 为场点至圆心的联线与y 轴的夹角.半圆线圈上d l 段线电流所受的力为:θθμd sin 2210R R I I π=2分θcos d d F F y =.根据对称性知: F y =0d =⎰y F 2分θsin d d F F x = ,⎰π=0x x dF F ππ=2210I I μ2210I I μ=2分∴半圆线圈受I 1的磁力的大小为: 2210I I F μ=, 方向:垂直I 1向右. 2分6、解:(1) ⎰⎰⋅π==Sr l r I S B t d 2d )(0μ Φ⎰++π=tb t a r r l I v v d 20μt a tb l I v v ++π=ln 20μ 4分 (2) aba b lI t t π-=-==2)(d d 00v μΦE 4分。
南京信息工程大学试卷18-19学年 第2学期 大学物理I(1)理科 期末试卷A本试卷共 7 页;考试时间 120分钟;出卷时间 19 年 06月题号 一 二 三 四 五 六 七 八 总分 得分评阅人一.选择题 (每小题2分,共30分) (注:请将选择题答案填入下表中)题号1 2 3 4 5 6 7 8 9 10 答案题号 11 12 13 14 15 答案1.下面哪一种说法是正确的 ( )(A) 运动物体的加速度越大,速度越大;(B) 作直线运动的物体,加速度越来越小,速度也越来越小; (C) 切向加速度与速度方向一致时,质点运动加快; (D) 法向加速度越大,质点运动的法向速度变化越快。
2.设地球质量为M ,地球半径为R ,其自转角速度为ω,则地球赤道上空的同步卫星离地面高度是 ( )(A); (B) 132GM R ω⎛⎫- ⎪⎝⎭; (C) 0; (D) R 。
3.假设物体沿着铅直面上圆弧形轨道下滑,轨道是光滑的,如图所示,在从A 至C 的下滑过程中,下面哪个说法是正确的?( )(A) 它的加速度方向永远指向圆心;(B) 它的合外力大小变化,方向永远指向圆心; (C) 它的速率均匀增加;密 封 线(D) 轨道支持力的大小不断增加。
4.质量为m 的物体用细绳水平拉住,静止在倾角为θ的光滑斜面上,如图所示,细绳给予物体的拉力为 ( )(A) g m ; (B) gsin m θ; (C) g cot m θ; (D) gsin cos m θθ。
5.一质量为M 、半径为r 的均匀圆环挂在一钉子上,以钉为轴在自身平面内作幅度很小的简谐振动。
圆环对转动轴(钉子)的转动惯量为 ( )(A) 2Mr ; (B) 2/2Mr ; (C) 23/2Mr ; (D) 22Mr 。
6.假设卫星环绕地球中心作圆周运动,则在运动过程中,卫星对地球中心的 ( )(A) 角动量守恒,动能也守恒; (B) 角动量守恒,动能不守恒; (C) 角动量不守恒,动能守恒; (D) 角动量守恒,动量也守恒。
2018-2019学年江西省南昌八中、南昌二十三中等四校联考高一(下)期中物理试卷★祝考试顺利★注意事项:1、答题前,请先将自己的姓名、准考证号用0.5毫米黑色签字笔填写在试题卷和答题卡上的相应位置,并将准考证号条形码粘贴在答题卡上的指定位置。
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一、单选题(本大题共8小题,共32.0分)1.关于曲线运动和圆周运动,下列说法中不正确的是()A. 曲线运动一定是变速运动B. 做曲线运动的物体的合力一定不为零C. 匀速圆周运动是速率不变的运动D. 做圆周运动的物体的加速度一定指向圆心【答案】D【解析】【详解】曲线运动的速度方向沿曲线的切线方向,是不断变化的,所以曲线运动一定是变速运动,故A正确;曲线运动的条件是合力方向与速度方向不共线,所以做曲线运动的物体的合力一定不为零。
故B正确;匀速圆周运动的速度大小不变,即速率不变,故C正确;匀速圆周运动的加速度的方向指向圆心,但一般的圆周运动的加速度的方向不一定指向圆心,故D错误;本题选择错误的,故选D。
2.如图,物体A和B的质量均为m,且分别与跨过定滑轮的轻绳连接(不计绳与滑轮、滑轮与轴之间的摩擦),在用水平变力F拉物体B沿水平方向向右做匀速直线运动的过程中()A. 物体A也做匀速直线运动B. 物体A做减速直线运动C. 绳子拉力始终大于物体A所受重力D. 绳子拉力始终小于物体A所受重力【答案】C【解析】【详解】设绳子与水平方向的夹角为α,将B的速度分解为沿绳子方向和垂直于绳子方向,沿绳子方向的分速度等于A的速度,有v A=v B cosα.B向右做匀速直线运动,则θ减小,则A 的速度增大,A做加速运动。
1.(10分)一容器内储有1 mol氧气,其压强为1.01⨯105Pa,温度为27o C,试求:(1)单位体积中分子数n;(2)氧气分子质量m0;(3)气体密度ρ;(4)氧气分子的平动动能εk;(5)氧气的内能。
2.(10分)设想每秒有1023个氧分子以500 m/s的速度沿着与器壁法线成45o角的方向撞在面积为2⨯10-4 m2的器壁上,求这群分子作用在器壁上的压强。
3.(20分)1 mol氢气,在压强为P0时,温度T0时,其体积为V0,今使其经过下面两种过程到达同一状态:(1)先保持体积不变,加热使其温度升高到2T0,然后等温膨胀到体积3V0;(2)先等温膨胀到体积3V0,然后等体加热到2T0。
问:两种过程所吸收的热量是否相等,如果不相等,则吸收的热量各为多少?(题中各参数单位分别为压强Pa、温度K和体积m3)4.(25分)如下图所示为1 mol某种双原子分子理想气体所经历的循环过程,其中ac为等温线,已知状态a和c的体积大小分别为V0和2V0,求循环效率。
5.(25分)如下图所示,一长方形木块浮于静水中,其浸入部分高为a,今用手指沿竖直方向将其慢慢压下,然后放手任其运动,试证明:若不计阻力,木块运动为简谐振动,并求出振动周期(设重力加速度为g)。
6.(10分)一横波沿绳子传播时的波动表式为ξ=0.5cos(10πt-4πx),x和ξ的单位为m, t的单位为s。
(1)求此波的振幅、波速、频率和波长;(2)求绳子上各质点振动的最大速度和最大加速度;(3)求x = 0.2m 处的质点在t =1s 时的相位,它是原点处质点在哪一时刻的相位? (4)如果绳的线密度为ρl =0.05kg/m,求绳中的张力F。
1.(10分)一容器内储有2 mol氧气,其压强为1.01⨯105Pa,温度为27o C,试求:(1)单位体积中分子数n;(2)氧气分子质量m0;(3)气体密度ρ;(4)氧气分子的平动动能εk;(5)氧气的内能。
2019年大学物理期末考试题库300题含答案一、选择题1.一个转动惯量为J 的圆盘绕一固定轴转动,初角速度为0ω。
设它所受阻力矩与转动角速度成正比M=ωk -(k 为正常数)(1)它的角速度从0ω变为0ω/2所需时间是 ( ) (A) J /2; (B) J /k ; (C) (J /k )ln 2; (D) J /2k 。
(2)在上述过程中阻力矩所作的功为 ( )(A) J 20ω/4; (B) -3J 20ω/8; (C) -J 20ω/4; (D) J 20ω/8。
2.在下面几种说法中,正确的是: ( )(A )波源不动时,波源的振动周期与波动的周期在数值上是不同的; (B )波源振动的速度与波速相同;(C )在波传播方向上,任一质点的振动位相总是比波源的位相滞后; (D )在波传播方向上,任一质点的振动位相总是比波源的位相超前。
3.一个质点作简谐振动,周期为T ,当质点由平衡位置向x 轴正方向运动时,由平衡位置到二分之一最大位移这段路程所需要的最短时间为: ( ) (A )T /4; (B )T /12; (C )T /6; (D )T /8。
4.在单缝衍射实验中,缝宽a =0.2mm ,透镜焦距f =0.4m ,入射光波长λ=500nm ,则在距离中央亮纹中心位置2mm 处是亮纹还是暗纹?从这个位置看上去可以把波阵面分为几个半波带? ( )(A) 亮纹,3个半波带; (B) 亮纹,4个半波带; (C) 暗纹,3个半波带; (D) 暗纹,4个半波带。
5.电荷分布在有限空间内,则任意两点P 1、P 2之间的电势差取决于 ( ) (A) 从P 1移到P 2的试探电荷电量的大小; (B) P 1和P 2处电场强度的大小; (C) 试探电荷由P 1移到P 2的路径;(D) 由P 1移到P 2电场力对单位正电荷所作的功。
6.一束光强为I 0的自然光,相继通过三个偏振片P 1、P 2、P 3后出射光强为I 0 /8。
南昌大学20 18 ~2019 学年第 1 学期期终考试试卷
南昌大学2018~2019学年第1学期期终考试A(3)类A 卷解答
一、1. π 、- π /2 、π/3.
2. )21cos(04.0π+π=t x
3. ])330/(165cos[10.0π--π=x t y (SI)
4. )2
1
100cos()21cos(30.0π+ππ=t x y (SI)
5. 1.2 mm 3.6 mm
6. 125 rad/s 、 338 m/s 、 17m
7. 6 、 第一级明(只填“明”也可以)
8. 子波 、子波干涉(或答“子波相干叠加”) 9. 一 、三 10. 2I
二.、A 、B 、D 、 C 、C 、B 、B 、B 、B 、A 三、
1解:设物体的运动方程为 )c o s (φω+=t A x .
恒外力所做的功即为弹簧振子的能量: F ×0.05 = 0.5J .
当物体运动到左方最远位置时,弹簧的最大弹性势能为0.5 J ,即:
5.02
1
2=kA J , ∴ A = 0.204 m . 2分
A 即振幅. 4/2==m k ω (rad/s)2
ω = 2 rad/s . 2分 按题目所述时刻计时,初相为φ = π.∴ 物体运动方程为 2分
)2c o s (204.0π+=t x (SI). 2分
2解: x 2 = 3×10-2 sin(4t - π/6) = 3×10-2cos(4t - π/6- π/2) = 3×10-2cos(4t - 2π/3).
作两振动的旋转矢量图,如图所示. 图 2分
由图得:合振动的振幅和初相分别为
A = (5-3)cm = 2 cm ,φ = π/3. 4分
合振动方程为 x = 2×10-2cos(4t + π/3) (SI) 2分
3解:(1) 由P 点的运动方向,可判定该波向左传播. 原点O 处质点,t = 0 时
φc o s 2/2A A =, 0sin 0<-=φωA v
所以 4/π=φ
O 处振动方程为 )4
1
500cos(0π+π=t A y (SI) 3分
由图可判定波长λ = 200 m ,故波动表达式为
]4
1
)200250(2cos[π++
π=x t A y (SI) 2分 (2) 距O 点100 m 处质点的振动方程是
)4
5
500cos(1π+π=t A y 1分
x O
ω
π/3-2π/3A
1A 2
A
振动速度表达式是 )4
5
500cos(500π+ππ-=t A v (SI) 2分
4解:(1) ∆x =20 D λ / a
=0.11 m 2分
(2) 覆盖云玻璃后,零级明纹应满足
(n -1)e +r 1=r 2 2分 设不盖玻璃片时,此点为第k 级明纹,则应有
r 2-r 1=k λ 2分 所以 (n -1)e = k λ
k =(n -1) e / λ=6.96≈7 零级明纹移到原第7级明纹处 2分
5答:由题意,(n 2 / n 1)=tg i 0.设第一界面上折射角为r ,它也等于第二界面上的入射角.若要第二界面反射光是线偏振光,r 应等于起偏角,即
n 3 / n 2=tg r 3分 因为i 0是起偏角,∴i 0+r =90°.tg r =ctg i 0.
由此得 n 2 / n 3=n 2 / n 1 3分 不论n 2是多少,只要n 1=n 3就能满足要求. 2分。