广东工业大学847大学物理学2018年考研真题

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广东工业大学考研历年真题

广东工业大学考研历年真题【第一部分:单项填空】1. However, some actors _____ us with the deep feelings they can inspire in us for a character they are playing. [单选题] *A.astonishedB. astonishingC. astonish(正确答案)D. is astonished2. He was a _____ figure in the French film industry. [单选题] *A. dominantlyB. dominant(正确答案)C. dominanceD. dominants3. The morning after your arrival, you meet with the _____ physician for a private consultation. [单选题] *A. residentsB. resident(正确答案)C. residenceD. residences4._____a reply, he decided to write again. [单选题] *A. Not receivingB. ReceivingC. Not having received(正确答案)D. Having not received5.With lots of trees and flowers _____here and there, the city looks very beautiful. [单选题] *A. having plantedB. planted(正确答案)C. have been plantedD. to be planted6. I have bought two ball-pens, _______ writes well. [单选题] *A. none of themB. neither of themC. neither of which(正确答案)D. none of which7.Great changes have taken place since then in the factory _______we are working. [单选题] *A.where(正确答案)B.hatC.whichD.there8.The engineer ______my father works is about 50 years old. [单选题] *A. to whomB. on whomC. with whichD. with whom(正确答案)9.The reason ______he didn't come was ______he was ill. [单选题] *A. why; that(正确答案)B.that;whyC. for that;thatD.for which;what10. Is _______ some German friends visited last week? [单选题] *A. this schoolB. this the schoolC. this school oneD. this school where(正确答案)11. They are not very good, but we like_______. [单选题] *A. anyway to play basketball with themB. to play basketball with them anyway(正确答案)C. to play with them basketball anywayD. with them to play basketball anyway12. He sent me an e-mail, _______to get further information. [单选题] *A. hopedB hoping(正确答案)C. to hopeD. hope13._____in 1636, Harvard is one of the most famous universities in the United States. [单选题] *A. Being roundedB it was foundedC. Founded(正确答案)D. Founding14.The ____boy was last seen ______near the East Lake. [单选题] *A. Missing, playing(正确答案)B. missing, playC missed, playedD missed, to play15. Tony was very unhappy for _______ to the party. [单选题] *A. having not been invitedB. not having invitedC. having not invitedD not having been invited(正确答案)【第二部分:完形填空】A new study found that inner-city kids living in neighborhoods with more green spacegained about 13% less weight over a two-year period than kids living amid more concrete and fewer trees. Such __62__ tell a powerful story. The obesity epidemic began in the 1980s, and many people __63__ it to increased portion sizes and inactivity, but that can't be everything. Fast foods and TVs have been __64__ us for a long time. "Most experts agree that the changes were __65__ to something in the environment," says social epidemiologist Thomas Glass of The Johns Hopkins Bloomberg School of Public Health. That something could be a __66__ of the green.The new research, __67__ in the American Journal of Preventive Medicine, isn't the first to associate greenery with better health, but it does get us closer __68__ identifying what works and why. At its most straightforward, a green neighborhood __69__ means more places for kids to play – which is __70__ since time spent outdoors is one of the strongest correlates of children's activity levels. But green space is good for the mind__71__: research by environmental psychologists has shown that it has cognitive __72__ for children with attention-deficit disorder. In one study, just reading __73__ in a green setting improved kids' symptoms.__74__ to grassy areas has also been linked to __75__ stress and a lower body mass index (体重指数) among adults. And an __76__ of 3,000 Tokyo residents associated walkable green spaces with greater longevity (长寿) among senior citizens.Glass cautions that most studies don't __77__ prove a causal link between greenness and health, but they're nonetheless helping spur action. In September the U. S. House of Representatives __78__ the delightfully named No Child Left Inside Act to encourage public initiatives aimed at exposing kids to the outdoors.Finding green space is not __79__ easy, and you may have to work a bit to get your family a little grass and trees. If you live in a suburb or a city with good parks, take__80__ of what's there. Your children in particular will love it – and their bodies and minds will be __81__ to you.16. [单选题] *A) findings(正确答案)B) thesesC) hypothesesD) abstracts17. [单选题] *A) adaptB) attribute(正确答案)C) allocateD) alternate18. [单选题] *A) amongstB) alongC) besideD) with(正确答案)19. [单选题] *A) gluedB) related(正确答案)C) trackedD) appointed20. [单选题] *A) scrapingB) denyingC) depressingD) shrinking(正确答案)21. [单选题] *A) published(正确答案)B) simulatedC) illuminatedD) circulated22. [单选题] *A)atB)to(正确答案)C)forD)over23. [单选题] *A) fullyB) simply(正确答案)C) seriouslyD) uniquely24. [单选题] *A)vital(正确答案)B)casualC)fatalD)subtle25. [单选题] *A) stillB) alreadyC) too(正确答案)D) yet26. [单选题] *A) benefits(正确答案)B) profitsC) revenuesD) awards27. [单选题] *A) outwardB) apartC) asideD) outside(正确答案)28. [单选题] *A) ImmunityB) ReactionC) Exposure(正确答案)D) Addiction29. [单选题] *A)muchB)less(正确答案)C)moreD)little30. [单选题] *A) installmentB) expeditionC) analysis(正确答案)D) option31. [单选题] *A) curiouslyB) negativelyC) necessarily(正确答案)D) comfortably32. [单选题] *A) relievedB) delegatedC) approved(正确答案)D) performed33. [单选题] *A)merelyB)always(正确答案)C)mainlyD)almost34. [单选题] *A) advantage(正确答案)B) exceptionC) measureD) charge35. [单选题] *A) elevatedB) mercifulC) contentedD) grateful(正确答案)【第三部分:阅读理解】Passage 1Will there ever be another Einstein? This is the undercurrent of conversation at Einstein memorial meetings throughout the year. A new Einstein will emerge, scientists say. But it may take a long time. After all, more than 200 years separated Einstein from his nearest rival, Isaac Newton.Many physicists say the next Einstein hasn’t been born yet, or is a baby now. That’s because the quest for a unified theory that would account for all the forces of nature has pushed current mathematics to its limits. New math must be created before the problem can be solved.But researchers say there are many other factors working against another Einsteinemerging anytime soon.For one thing, physics is a much different field today. In Einstein’s day, there were only a few thousand physicists worldwide, and the theoreticians who could intellectually rival Einstein probably would fit into a streetcar with seats to spare.Education is different, too. One crucial aspect of Einstein’s training that is overlooked is the years of philosophy he read as a teenager—Kant, Schopenhauer and Spinoza, among others. It taught him how to think independently and abstractly about space and time, and it wasn’t long before he became a philosopher himself.“The independence created by philosophical insight is—in my opinion—the mark of distinction between a mere artisan (工匠) or specialist and a real seeker after truth,”Einstein wrote in 1944.And he was an accomplished musician. The interplay between music and math is well known. Einstein would furiously play his violin as a way to think through a knotty physics problem.Today, universities have produced millions of physicists. There aren’t many jobs in science for them, so they go to Wall Street and Silicon Valley to apply their analytical skills to more practical—and rewarding—efforts.“Maybe there is an Einstein out there today,” said Columbia University physicist Brian Greene, “but it would be a lot harder for him to be heard.”Especially considering what Einstein was proposing.“The actual fabric of space and time curving? My God, what an idea!” Greene said at a recent gathering at the Aspen Institute. “It takes a certain type of person who will bang his head against the wall because you believe you’ll find the solution.”Perhaps the best examples are the five scientific papers Einstein wrote in his “miracle year” of 1905. These “thought experiments” were pages of calculations signed and submitted to the prestigious journal Annalen der Physik by a virtual unknown. There were no footnotes or citations.What might happen to such a submission today?“We all get papers like those in the mail,” Greene said. “We put them in the junk file.”36. What do scientists seem to agree upon, judging from the first two paragraphs? [单选题] *[A] Einstein pushed mathematics almost to its limits.[B] It will take another Einstein to build a unified theory.[C] No physicist is likely to surpass Einstein in the next 200 years.[D] It will be some time before a new Einstein emerges.(正确答案)37. What was critical to Einstein’s success? [单选题] *[A] His talent as an accomplished musician.[B] His independent and abstract thinking.(正确答案)[C] His untiring effort to fulfill his potential.[D] His solid foundation in math theory.38. What does the author tell us about physicists today? [单选题] *[A] They tend to neglect training in analytical skills.[B] They are very good at solving practical problems.[C] They attach great importance to publishing academic papers.[D] They often go into fields yielding greater financial benefits.(正确答案)39. What does Brian Greene imply by saying “... it would be a lot harder for him to be heard” (Lines 1-2, Para. 9)? [单选题] *[A] People have to compete in order to get their papers published.[B] It is hard for a scientist to have his papers published today.[C] Papers like Einstein’s would unlikely get published today.[D] Nobody will read papers on apparently ridiculous theories.(正确答案)40. When he submitted his papers in 1905, Einstein _______. [单选题] *[A] forgot to make footnotes and citations[B] was little known in academic circles(正确答案)[C] was known as a young genius in math calculations[D] knew nothing about the format of academic papersPassage 2The relationship between formal education and economic growth in poorcountries is widely misunderstood by economists and politicians alike. Progress in both areas is undoubtedly necessary for the social, political, and intellectual development of these and all other societies; however, the conventional view that education should be one of the very highest priorities for promoting rapid economic development in poor countries is wrong. We are fortunate that it is, because building new educational systems there and putting enough people through them to improve economic performance would require two or three generations. The findings of a research institution have consistently shown that workers in all countries can be trained on the job to achieve radically higher productivity and, as a result, radically higher standards ofliving.Ironically, the first evidence for this idea appeared in the United States. Not long ago, with the country entering a recession and Japan at its pre-bubble peak, the U.S. workforce was derided as poorly educated and one of the primary causes of the poor U.S. economic performance. Japan was, and remains, the global leader in automotive-assembly productivity. Yet the research revealed that the U.S. factories of Honda, Nissan, and Toyota achieved about 95 percent of the productivity of their Japanese counterparts - a result of the training that U.S. workers received on the job.More recently, while examining housing construction, the researchers discoveredthat illiterate, non-English-speaking Mexican workers in Houston, Texas, consistently met best-practice labor productivity standards despite the complexity of the building industry's work.What is the real relationship between education and economic development? Wehave to suspect that continuing economic growth promotes the development of education even when governments don't force it. After all, that's how education got started. When our ancestors were hunters and gatherers 10, 000 years ago, they didn't have time to wonder much about anything besides finding food. Only when humanity began to get its food in a more productive way was there time for other things.As education improved, humanity's productivity potential increased as well.When the competitive environment pushed our ancestors to achieve that potential,they could in tum afford more education. This increasingly high level of education is probably a necessary, but not a sufficient, condition for the complex political systems required by advanced economic performance. Thus poor countries might not be ableto escape their poverty traps without political changes that may be possible only with broader formal education. A lack of formal education, however, doesn't constrain the ability of the developing world's workforce to substantially improve productivity forthe foreseeable future. On the contrary, constraints on improving productivity explain why education isn't developing more quickly there than it is.41. The author holds in Paragraph 1 that the importance of education in poor [单选题] * countries[A] is subject to groundless doubts.[B] has fallen victim of bias.[C] is conventionally downgraded.[D] has been overestimated.(正确答案)42. It is stated in Paragraph 1 that the construction of a new educational system [单选题] *[A] challenges economists and politicians.[B] takes efforts of generations.(正确答案)[C] demands priority from the government.[D] requires sufficient labor force.43. A major difference between the Japanese and U.S. workforces is that [单选题] *[A] the Japanese workforce is better disciplined.[B] the Japanese workforce is more productive.(正确答案)[C] the U.S. workforce has a better education.[D] the U.S. workforce is more organized.44. The author quotes the example of our ancestors to show that education emerged [单选题] *[A] when people had enough time.[B] prior to better ways of finding food.[C] when people no longer went hungry.(正确答案)[D] as a result of pressure on government.45. According to the last paragraph, development of education [单选题] *[A] results directly from competitive environments.[B] does not depend on economic performance.[C] follows improved productivity.(正确答案)[D] cannot afford political changes.Passage 3A symbiotic relationship is an interaction between two or more species in which one species lives in or on another species. There are three main types of symbiotic relationships: parasitism, commensalism, and mutualism. The first and the third can be key factors in the structure of a biological community; that is, all the populations oforganisms living together and potentially interacting in a particular area.Parasitism is a kind of predator-prey relationship in which one organism, the parasite, derives its food at the expense of its symbiotic associate, the host. Parasites are usually smaller than their hosts. An example of a parasite is a tapeworm that lives inside the intestines of a larger animal and absorbs nutrients from its host. Natural selection favors the parasites that are best able to find and feed on hosts. At the same time, defensive abilities of hosts are also selected for. As an example, plants make chemicals toxic to fungal and bacterial parasites, along with ones toxic to predatory animals (sometimes they are the same chemicals). In vertebrates, the immune system provides a multiple defense against internal parasites.At times, it is actually possible to watch the effects of natural selection in host-parasite relationships. For example, Australia during the 1940 s was overrun by hundreds of millions of European rabbits. The rabbits destroyed huge expanses of Australia and threatened the sheep and cattle industries. In 1950, myxoma virus, a parasite that affects rabbits, was deliberately introduced into Australia to control the rabbit population. Spread rapidly by mosquitoes, the virus devastated the rabbit population. The virus was less deadly to the offspring of surviving rabbits, however, and it caused less and less harm over the years. Apparently, genotypes (the genetic make-up of an organism) in the rabbit population were selected that were better able to resist the parasite. Meanwhile, the deadliest strains of the virus perished with their hosts as natural selection favored strains that could infect hosts but not kill them. Thus, natural selection stabilized this host-parasite relationship.In contrast to parasitism, in commensalism, one partner benefits without significantly affecting the other. Few cases of absolute commensalism probably exist, because it is unlikely that one of the partners will be completely unaffected. Commensal associations sometimes involve one species' obtaining food that is inadvertently exposed by another. For instance, several kinds of birds feed on insects flushed out of the grass by grazing cattle. It is difficult to imagine how this could affect the cattle, but the relationship may help or hinder them in some way not yet recognized.The third type of symbiosis, mutualism, benefits both partners in the relationship Legume plants and their nitrogen-fixing bacteria, and the interactions between flowering plantsand their pollinators, are examples of mutualistic association. In the first case, the plants provide the bacteria with carbohydrates and other organic compounds, and the bacteria have enzymes that act as catalysts that eventually add nitrogen to the soil, enriching it. In the second case, pollinators (insects, birds) obtain food from the flowering plant, and the plant has its pollen distributed and seeds dispersed much more efficiently than they would be if they were carried by the wind only. Another example of mutualism would be the bull's horn acacia tree, which grows in Central and South America. The tree provides a place to live for ants of the genus Pseudomyrmex. The ants live in large, hollow thorns and eat sugar secreted by the tree. The ants also eat yellow structures at the tip of leaflets: these are protein rich and seem to have no function for the tree except to attract ants. The ants benefit the host tree by attacking virtually anything that touches it. They sting other insects and large herbivores (animals that eat only plants) and even clip surrounding vegetation that grows near the tree. When the ants are removed, the trees usually die, probably because herbivores damage them so much that they are unable to compete with surrounding vegetation for light and growing space.The complex interplay of species in symbiotic relationships highlights an important point about communities: Their structure depends on a web of diverse connections among organisms.46.Which of the following statements about commensalism can be inferred from paragraph 1? [单选题] *[A]It excludes interactions between more than two species.[B]It makes it less likely for species within a community to survive.[C]Its significance to the organization of biological communities is small.(正确答案)[D]Its role in the structure of biological populations is a disruptive one.47.According to paragraph 2. which of the following is true of the action of natural selection on hosts and parasites? [单选题] *[A]Hosts benefit more from natural selection than parasites do.[B]Both aggression in predators and defensive capacities in hosts are favored for species survival.(正确答案)[C]The ability to make toxic chemicals enables a parasite to find and isolate its host.[D]Larger size equips a parasite to prey on smaller host organisms.48.Which of the following can be concluded from the discussion in paragraph 3 about theAustralian rabbit population? [单选题] *[A]Human intervention may alter the host, the parasite. and the relationship between them.(正确答案)[B]The risks of introducing outside organisms into a biological community are not worth the benefits.[C]Humans should not interfere in host-parasite relationships.[D]Organisms that survive a parasitic attack do so in spite of the natural selection process.49.According to paragraph 3, all of the following characterize the way natural selectionstabilized the Australian rabbit population EXCEPT: [单选题] *[A]The most toxic viruses died with their hosts.[B]The surviving rabbits were increasingly immune to the virus.[C]The decline of the mosquito population caused the spread of the virus to decline.(正确答案)[D]Rabbits with specific genetic make-ups were favored.50.According to paragraph 5. which of the following is NOT true of the relationshipbetween the bull's horn acacia tree and the Pseudomyrmex ants? [单选题] *[A]Ants defend the host trees against the predatory actions of insects and animals.[B]The acacia trees are a valuable source of nutrition for the ants.[C]The ants enable the acacia tree to produce its own chemical defenses.(正确答案)[D]The ants protect the acacia from having to compete with surrounding vegetation.。

广东工业大学物理化学1试卷及参考答案(A卷)

广东工业大学物理化学1试卷（A卷）一、选择题（20分。

每小题2分）1、某一化学反应，已知其△rCp.m<0,则该反应的△rHm的数值随温度升高而（）A、增大，B、减少，C、不变，D、不能肯定2、影响化学平衡常数的因素有（）。

A、催化剂，B、浓度，C、压力，D、温度3、α、β相中都含有A,B两种物资，当达到两相平衡时，下列哪种情况是正确的（）A、υA(β)= υB(β)，B、υA(α)>υB(α)C、υA（α）=υA（β）；D、υA（α）=υB(β)。

4、海水的沸点为（）。

A、100℃，B、高于100℃，C、低于100℃，D、无法判断5、气相反应2A(g)+B(g)=2C是放热的，当反应达到平衡时可采用下列哪组条件，使平衡向右移动（）A,降低温度和降低压力；B，升高温度和增大压力C，升高温度和降低压力；D，降低温度和增大压力6，二组分理想液态混合物的蒸汽总压为（）A,介于两纯组分的蒸汽压之间；B，与混合物的组成无关；C，大于任一纯组分的蒸汽压；D，小于任一纯组分的蒸汽压。

7、在描述哼沸混合物时，下列各点中哪一点是不正确的（）A。

，与化合物一样具有确定的组成；B，不具有确定的组成；C，平衡气相和液态组成相同；D，恒沸点随外压的改变而改变。

8、若体系吸收200KJ·mol-1的热量，并对环境做功300KJmol-1，则内能变化为△U=（）A、100KJ·mol-1；B、-100KJ·mol-1；C、400KJ·mol-1；D、-400KJ·mol-19、NH3Cl（g）放入某抽真空的密闭容器中，按下式NH4Cl（s）=NH3（g）+HCl（g）分解达平衡时，（）。

A、C=3，P=2，F=3;B、C=2，P=2，F=2;C、C=1，P=2，F=1;D、C=2，P=3，F=1.10、纯物质在三相点时自由度为（）A,0; B,1; C,2; D,3二，填空题（20分。

最新-2018年普通高等学校招生全国统一考试(广东卷)物理(附答案) 精品

2018年普通高等学校招生全国统一考试（广东卷）物理试题本试卷分选择题和非选择题两部分，共8页，满分150分.考试用时120分钟.第一部分选择题（共40分）一、本题共10小题，每小题4分，共40分.在每小题给出的四个选项中，有的小题只有一个选项正确，有的小题有多个选项正确.全部选对的得4分，选不全的得2分，有选错的或不答的得0分.1.下列对运动的认识不正确的是A.亚里士多德认为物体的自然状态是静止的，只有当它受到力的作用才会运动B.伽利略认为力不是维持物体速度的原因C.牛顿认为力的真正效应总是改变物体的速度，而不仅仅是使之运动D.伽利略根据理想实验推论出，如果没有摩擦，在水平面上的物体，一旦具有某一个速度，将保持这个速度继续运动下去答案：A解析：物体的自然状态即平衡状态，是静止或匀速直线运动，物体做匀速直线运动时不需要受到力的作用，由于惯性就可以保持原来的运动状态.所以A 项说法是不正确的.从伽利略的理想斜面实验可得到物体的运动不需要力来维持，即力不是维持物体速度的原因，反而力是改变物体速度即使物体产生加速度的原因，所以BC 项正确.伽利略根据理想实验推论出，物体一旦具有某一个速度，将保持这个速度永远运动下去的结论，所以D 项正确.题目要求选不正确的选项，所以只有A 符合要求.2.a 、b 两物体从同一位置沿同一直线运动，它们的速度图象如图1所示，下列说法正确的是图1A.a 、b 加速时，物体a 的加速度大于物体b 的加速度B.20秒时，a 、b 两物体相距最远C.60秒时，物体a 在物体b 的前方D.40秒时，a 、b 两物体速度相等，相距200 m答案：C解析：a 、b 两物体同地同一直线运动，从速度图象看速度都为正值，即同向行驶.a 的加速度a=t v ∆∆=s s m 20/30=1.5 m/s 2,b 的加速度a′=t v '∆'∆=ss m 20/40=2 m/s 2. 所以a 物体的加速度小于b 物体的加速度，即A 项错误.20 s 时,a 物体速度达到v=40 m/s 而b 物体仍静止，只有当40 s 时，即a 、b 两物体的速度相等时，a 、b 两物体才相距最远，此时相距的距离为Δs=(800 m+500 m)-400 m=900 m,所以BD 项错误.当60 s 时a 的位移为s a =21×(10+40)×20 m+40×40 m=2 100 m而b 的位移s b =21×40×100 m=2 000 m,所以a 在b 的前方即C 项正确. 3.下列说法正确的是A.康普顿发现了电子B.卢瑟福提出了原子的核式结构模型C.贝克勒尔发现了铀和含铀矿物的天然放射现象D.伦琴发现了X 射线答案：BCD解析：汤姆生在1897年发现了电子，即A 项错误.卢瑟福通过α粒子散射实验提出了原子的核式结构，所以B 项正确.贝克勒尔发现了铀和含铀矿物具有天然放射现象，伦琴通过高速电子流打到物体上发现了X 射线即伦琴射线，在这些物理学史中只有BCD 项是正确的.4.关于永动机和热力学定律的讨论，下列叙述正确的是A.第二类永动机违反能量守恒定律B.如果物体从外界吸收了热量，则物体的内能一定增加C.外界对物体做功，则物体的内能一定增加D.做功和热传递都可以改变物体的内能，但从能量转化或转移的观点来看这两种改变方式是有区别的答案：D解析：第二类永动机并不违反能量守恒定律，它只不符合热力学第二定律，所以A 项错误.从热力学第一定律可知物体内能的改变ΔU 与物体吸、放热ΔQ 和做功ΔW 有关，即ΔU=ΔQ+ΔW.物体只从外界吸收了热量，做功情况不明确，同样道理，对物体做功而吸、放热情况不明确，都不能断定物体的内能如何变化，所以B 、C 项错误.做功是通过机械能转化为热能，而热传递是热能从一个物体转移到另一个物体，两种改变内能的方式和本质是有区别的，所以D 项正确.5.据新华社报道，由我国自行设计、研制的世界上第一套全超导核聚变实验装置（又称“人造太阳”）已完成了首次工程调试，下列关于“人造太阳”的说法正确的是A.“人造太阳”的核反应方程是n He H H 10423121+→+B.“人造太阳”的核反应方程是n Kr Ba n U 1092361415610235923++→+C.“人造太阳”释放的能量大小的计算式是ΔE=Δmc 2D.“人造太阳”核能大小的计算公式是E=21mc 2 答案：AC解析：“人造太阳”是利用海水中的H 21和H 31聚变而产生大量热量的.放出的热量可利用爱因斯坦质能方程ΔE=Δmc 2求出，其中Δm 为质量亏损，所以A 、C 项正确.而B 项核反应方程是U 23592的裂变方程，所以B 项错误，爱因斯坦质能方程E=21mc 2是计算质量m 的粒子所具有的能量，并不是计算由于核反应中质量亏损而产生的热量.所以D 项错误.6.铺设铁轨时，每两根钢轨接缝处都必须留有一定的间隙，匀速运行列车经过轨端接缝处时，车轮就会受到一次冲击.由于每一根钢轨长度相等，所以这个冲击力是周期性的，列车受到周期性的冲击做受迫振动.普通钢轨长为12.6 m ，列车固有振动周期为0.315 s.下列说法正确的是A.列车的危险速率为40 m/sB.列车过桥需要减速，是为了防止列车发生共振现象C.列车运行的振动频率和列车的固有频率总是相等的D.增加钢轨的长度有利于列车高速运行答案：AD解析：火车在行驶过程中与铁轨间隙间的碰撞，给火车施加了一个周期性的策动力，要使火车不发生危险，应使策动力的周期远离火车的固有周期，因固有周期T 0=0.315 s.所以策动力周期T=T 0=0.315 s 时使火车发生共振，振幅最大，最为危险，则由T=v L 得危险速度为v=T L =sm 315.06.12=40 m/s ，所以A 项正确.列车过桥时应防止桥梁发生共振导致桥梁坍塌.基本的做法是减小火车速度而不是防止列车发生共振，所以B 项错误.物体受迫振动时的振动频率总等于策动力的频率，与物体的固有频率无关，所以C 项错误.增加铁轨的长度，同时增大列车速度，使策动力频率远离火车的固有频率，是提高火车车速的一种措施.所以D 项正确.7.两束不同频率的单色光a 、b 从空气平行射入水中，发生了图2所示的折射现象（α>β).下列结论中正确的是图2A.光束b 的频率比光束a 低B.在水中的传播速度，光束a 比光束b 小C.水对光束a 的折射率比水对光束b 的折射率小D.若光束从水中射向空气，则光束b 的临界角比光束a 的临界角大答案：C解析：从折射光路图可知a 光的折射率小，则其频率小，在水中的传播速度v=c 知速度大.光从水射入空气的临界角C=arcsin n1，则a 光临界角大，所以只有C 项正确，ABD 项是错误的.8.图3为电冰箱的工作原理示意图.压缩机工作时，强迫致冷剂在冰箱内外的管道中不断循环.在蒸发器中致冷剂汽化吸收箱体内的热量，经过冷凝器时致冷剂液化，放出热量到箱体外，下列说法正确的是图3A.热量可以自发地从冰箱内传到冰箱外B.电冰箱的致冷系统能够不断地把冰箱内的热量传到外界，是因为其消耗了电能C.电冰箱的工作原理不违反热力学第二定律D.电冰箱的工作原理违反热力学第一定律答案：BC解析：在电冰箱的热量传递过程中是由于压缩机消耗电能做功才使热量从冰箱内传到冰箱外，并不是自发地进行，所以A项错误，B项正确.电冰箱的工作原理不违反热力学第一定律和能量守恒定律，所以C项正确，D项错误.9.目前雷达发射的电磁波频率多在200 MHz至1 000 MHz的范围内，下列关于雷达和电磁波说法正确的是A.真空中上述雷达发射的电磁波的波长范围在0.3 m至1.5 m之间B.电磁波是由恒定不变的电场或磁场产生的C.测出从发射电磁波到接收反射波的时间间隔可以确定雷达和目标的距离D.波长越短的电磁波，反射性能越强答案：ACD解析：由λ=c/f可求得200 MHz和1 000 MHz的电磁波波长分别为1.5 m和0.3 m,所以A项正确.电磁波地传播是由周期性变化的电场和周期性变化的磁场交替垂直产生由近及远地传播而形成电磁波，所以B项错误.通过电磁波的传播L=vt=ct可确定雷达和目标的距离，所以C项正确.波长越短的电磁波，其频率越大，粒子性越强即反射性越强，所以D项正确.10.如图4所示，用一根长为L质量不计的细杆与一个上弧长为l0、下弧长为d0的金属线框的中点联结并悬挂于O点，悬点正下方存在一个上弧长为2l0、下弧长为2d0的方向垂直纸面向里的匀强磁场，且d0L，先将线框拉开到如图4所示位置，松手后让线框进入磁场，忽略空气阻力和摩擦，下列说法正确的是图4A.金属线框进入磁场时感应电流的方向为a→b→c→d→aB.金属线框离开磁场时感应电流的方向为a→d→c→b→aC.金属线框dc边进入磁场与ab边离开磁场的速度大小总是相等D.金属线框最终将在磁场内做简谐运动答案：D解析：线框在进入磁场过程中由楞次定律可判得电流方向为a→d→c→b→a.而摆出磁场过程中同样由楞次定律可判得电流方向为a→b→c→d→a，所以A、B项均错误.因为线框在进入和离开磁场过程中，线圈中产生了感应电流，通过电阻发出了热量，而动能会逐渐减少，所以速度会逐渐减小，所以C项错误.线框最终在磁场中摆动过程中，由于磁通量不再发生变化，回路中不再产生感应电流没有热能的产生，只有机械能的转化与守恒，所以线框最终会在磁场中做简谐运动，则D项正确.第二部分非选择题（共110分）二、本题共8小题，共110分.按题目要求作答.解答题应写出必要的文字说明、方程式和重要演算步骤.只写出最后答案的不能得分.有数值计算的题，答案中必须明确写出数值和单位.11.（9分）某同学设计了一个研究平抛运动的实验.实验装置示意图如图5所示，A是一块平面木板，在其上等间隔地开凿出一组平行的插槽（图5中P0P0′、P1P1′……），槽间距离均为d.把覆盖复写纸的白纸铺贴在硬板B上.实验时依次将B板插入A板的各插槽中，每次让小球从斜轨的同一位置由静止释放.每打完一点后，把B板插入后一槽中并同时向纸面内侧平移距离d.实验得到小球在白纸上打下的若干痕迹点，如图6所示.图5 图6（1）实验前应对实验装置反复调节，直到___________.每次让小球从同一位置由静止释放，是为了____________________________________________.（2）每次将B板向内侧平移距离d，是为了______________________.（3）在图6中绘出小球做平抛运动的轨迹.答案：（1）斜轨末段水平、A板水平、插槽P0P0′垂直斜轨并在斜轨末端正下方（2）使记录纸上每两点之间的水平距离等于小球在水平方向实际运动的距离（3）见解析图解析：（1）研究平抛运动的规律，首要的一点是使小球沿水平方向抛出.所以实验前要反复调节斜槽，使斜槽的末端处于水平状态，并使板A水平，插槽P0P0′垂直斜轨并在斜轨末端正下方.斜放小球时，每次要使小球从斜槽的同一位置滑下的主要原因是为了使小球每次抛出时具有同样的水平初速度v0.（2）实验过程中，竖直木板在后移d的同时也平向移动d，是为了让每次的小球落点不在记录纸面的竖直直线上，而在侧移了的平面上，使记录纸上每两点之间的水平距离等于小球在水平方向实际运动的距离.由水平方向的匀速运动研究竖直方向的运动规律.（3）小球的平抛运动轨迹如图.12.（11分）某同学设计了一个如图7所示的实验电路，用以测定电源电动势和内阻，使用的实验器材为：待测干电池组（电动势约3 V0.6 A，内阻小于1 Ω）、电阻箱（0—99.99 Ω）、滑动变阻器（0—10 Ω）、单刀双掷开关、单刀单掷开关各一个及导线若干.考虑到干电池的内阻较小，电流表的内阻不能忽略.（1）该同学按图7连线，通过控制开关状态，测得电流表内阻约为0.20 Ω.试分析该测量产生误差的原因是_______________________________________________________.（2）简要写出利用图7所示电路测量电源电动势和内阻的实验步骤：①_____________________________________________________________________________; ②_____________________________________________________________________________.图7 图8（3）图8是由实验数据绘出的I1R 图象，由此求出待测干电池组的电动势E=___________V 、内阻r=___________Ω.（计算结果保留三位有效数字）答案：（1）满偏时滑动变阻器阻值与电流表阻值之比偏低；电阻箱的阻值不能连续调节.（2）①断开K ，将R 旋至最大值，S 掷向D ；②调小R 直到电流表指针有足够偏转，改变R 值测出几组I 随R 变化的数据.（3）E=2.86 V(2.76—2.96 V 均给分）r=2.37 Ω(2.37—2.47 Ω均给分)解析：先测电流表内阻：K 闭合，S 断开，调节滑动变阻器的滑片P 使电流表A 满偏，再将S 接通C ，调节电阻箱R 使电流表A 半偏.此时电阻箱R 的阻值即为电流表A 的内阻.因为电流表满偏时I=0.6 A 、电动势E 约为3 V ，则回路中电阻约为R=I E =AV 6.03=5 Ω.所以测得的电流表内阻有误差的主要原因是滑动变阻器的阻值没有满足R ＞＞R A 和电阻箱不能连续调节.再测电源的电动势和内阻：K 断开，电阻值箱R 阻值旋为最大值.S 接通D ，调节电阻箱R 的阻值，读出若干组R 对应的电流.描点画图得到I1-R 图象. 由E=I （R+R A +r ）可得I 1=E R +E r R A +，所以图象的斜率k=E 1得8.89.04-=E 1得E=284 V由纵轴截距Er R A +=0.9得r=2.37 Ω. 13.（15分）（1）人们发现光电效应具有瞬时性和对各种金属都存在极限频率的规律.请问谁提出了何种学说很好地解释了上述规律？已知锌的逸出功为3.34 eV ，用某单色紫外线照射锌板时，逸出光电子的最大速度为118 m/s ，求该紫外线的波长λ（电子质量m e =9.11×10-31 kg ，普朗克常量h=6.63×10-34 J ·s,1 eV=1.60×10-19 J ）.（2）风力发电是一种环保的电能获取方式.图9为某风力发电站外观图.设计每台风力发电机的功率为40 kW.实验测得风的动能转化为电能的效率约为20%，空气的密度是1.29 kg/m 3，当地水平风速约为10 m/s ，问风力发电机的叶片长度约为多少才能满足设计要求？图9答案：（1）2.01×10-7 m （2）10 m解析：（1）（7分）爱因斯坦提出了光子学说很好地解释了光电效应. ① 根据爱因斯坦光电效应方程hc/λ=W+21m e v 2 ② 所以λ=2.01×10-7 m. ③(2)(8分)风的动能：E k =21mv 2 ① 风t 时间内通过叶片为半径圆的质量：m=ρV=ρπl 2vt ② P=t E k =21ρπl 2v 3η ③ 由①②③得：l≈10 m.14.（12分）某发电站的输出功率为118 kW ，输出电压为4 kV ，通过理想变压器升压后向80 km 远处用户供电.已知输电线的电阻率为ρ=2.4×10-8 Ω·m ，导线横截面积为1.5×10-4 m 2，输电线路损失的功率为输出功率的4%，求：（1）升压变压器的输出电压；（2）输电线路上的电压损失.答案：（1）80 000 V （2）3 200 V解析：（1）输电线的电阻为：R=ρSl 2 ① P 损=P 1×4% ② P 损=I 22R ③ P 2=P 1 ④ P 2=I 2U 2 ⑤ 由①②③④⑤得升压变压器的输出电压：U 2=80 000 V.（2）输电线路上的电压损失U 损=I 2R=3 200 V .15.（14分）一个质量为4 kg 的物体静止在足够大的水平地面上，物体与地面间的动摩擦因数μ=0.1.从t=0开始，物体受到一个大小和方向呈周期性变化的水平力F 作用，力F 随时间的变化规律如图10所示.求83秒内物体的位移大小和力F 对物体所做的功.g 取10 m/s 2.图10答案：167 m 676 J解析：一个运动周期时间为4秒，半个周期t=2秒.物体所受到的摩擦力大小为：f=μmg前2秒内物体的加速度：a 1=mf F -1 2—4秒物体的加速度：a 2=mf F -2 s 1=21a 1t 2 s 2=v 1t+21a 2t 2 v 1=a 1t 前4秒的位移大小：s=s 1+s 2第84秒的位移s 0=-21a 2(2t )2 83秒时的速度v=-a 2(2t ) 83秒内的位移大小：s 83=21s-s 0s 83=167 m83秒内外力F 对物体做的功为：W F =21mv 2+fs 83 W F =676 J.16.（16分）如图11所示，在磁感应强度大小为B 、方向垂直向上的匀强磁场中，有一上、下两层均与水平面平行的“U ”型光滑金属导轨，在导轨面上各放一根完全相同的质量为m 的匀质金属杆A 1和A 2，开始时两根金属杆位于同一竖直面内且杆与轨道垂直.设两导轨面相距为H ，导轨宽为L ，导轨足够长且电阻不计，金属杆单位长度的电阻为r.现有一质量为2m的不带电小球以水平向右的速度v 0撞击杆A 1的中点，撞击后小球反弹落到下层面上的C 点.C 点与杆A 2初始位置相距为s.求：（1）回路内感应电流的最大值；（2）整个运动过程中感应电流最多产生了多少热量；（3）当杆A 2与杆A 1的速度比为1∶3时，A 2受到的安培力大小.图11答案：（1）r H g sv B 4)2(0+（2）Q=161m(v 0+s Hg 2)2（3）F=)2(802Hg s v r L B + 解析：（1）小球撞击杆瞬间动量守恒，之后做平抛运动，设小球碰撞后速度大小为v 1,杆获得速度大小为v 2,则2m v 0=-2m v 1+mv 2 s=v 1t H=21gt 2 v 2=21(v 0+s Hg 2) 杆在磁场中运动，其最大电动势为E 1=BLv 2 最大电流I max =Lr E 21 I max =r H g sv B 4)2(0+.（2）两金属杆在磁场中运动始终满足动量守恒.两杆最终速度相同，设为v′mv 2=2mv′ Q=21mv 22-21×2mv′2 Q=161m(v 0+s Hg 2)2. (3)设杆A 2和A 1的速度大小分别为v 和3vmv 2=mv+m3v I=LrE 22 安培力F=BIL F=r L B 82(v 0+s Hg 2). 17.（16分）宇宙中存在一些离其它恒星较远的、由质量相等的三颗星组成的三星系统，通常可忽略其它星体对它们的引力作用.已观测到稳定的三星系统存在两种基本的构成形式：一种是三颗星位于同一直线上，两颗星围绕中央星在同一半径为R 的圆轨道上运行；另一种形式是三颗星位于等边三角形的三个顶点上，并沿外接于等边三角形的圆轨道运行.设每个星体的质量均为m.（1）试求第一种形式下，星体运动的线速度和周期；（2）假设两种形式星体的运动周期相同，第二种形式下星体之间的距离应为多少？答案：（1）v=R GmR 25 T=4πGmR 53 （2）r=31)512(R 解析：（1）对于第一种运动情况，以某个运动星体为研究对象，根据牛顿第二定律和万有引力定律有：F 1=22R Gm F 2=22)2(R Gm F 1+F 2=mv 2/R ① 运动星体的线速度：v=R GmR 25 ② 周期为T ，则有： T=vR π2 ③ T=4πGmR 53. ④ (2)设第二种形式星体之间的距离为r ，则三个星体做圆周运动的半径为 R′= 30cos 2/r ⑤由于星体做圆周运动所需要的向心力靠其它两个星体的万有引力的合力提供.由力的合成和牛顿运动定律有：F 合= 30cos 222rGm ⑥ F 合=m 224TπR′ ⑦ 由④⑤⑥⑦式得：r=31)512(R. 18.（17分）在光滑绝缘的水平桌面上，有两个质量均为m ，电荷量为+q 的完全相同的带电粒子P 1和P 2，在小孔A 处以初速度为零先后释放.在平行板间距为d 的匀强电场中加速后，P 1从C 处对着圆心进入半径为R 的固定圆筒中（筒壁上的小孔C 只能容一个粒子通过），圆筒内有垂直水平面向上的磁感应强度为B 的匀强磁场.P 1每次与筒壁发生碰撞均无电荷迁移，P 1进入磁场第一次与筒壁碰撞点为D ，∠COD=θ，如图12所示.延后释放的P 2，将第一次欲逃逸出圆筒的P 1正碰回圆筒内，此次碰撞刚结束，立即改变平行板间的电压，并利用P 2与P 1之后的碰撞，将P 1限制在圆筒内运动.碰撞过程均无机械能损失.设d=85πR ，求：在P 2和P 1相邻两次碰撞时间间隔内，粒子P 1与筒壁的可能碰撞次数.附：部分三角函数值图12答案：2，3，4，5，6，7解析：设开始加速电压为U 1，P 1、P 2第一次碰撞后电压变为U 2 qU 1=21mv 02①Bv 0q=mrv 2②设粒子在圆筒中与筒壁碰撞（n-1）次，转了k 圈后从C 点射出，运动时间为t 1nθ=2kπ ③ tan 2θ=Rr④ T 0=2v rπ t 1=n×πθπ2-T 0 ⑤ P 2在电场中运动时间为t 2,欲使P 1不逃逸出磁场有： mv 0+m(-v 0)=mv 1+mv 221mv 02+21mv 02=21mv 12+21mv 22 ⑥ v 1=-v 2 ⑦v 1=-v 0,v 2=v 0P 1、P 2碰撞后速度发生交换t 2=2022qU mdv a v =⑧ 欲使P 2与P 1碰撞后不穿出A 点，与P 1碰撞后P 2返回距离为s ，12U U =sd≥1有U 2≥U 1 ⑨ t 1=t 2 ⑩ 由⑤⑧⑩得：U 2=)2(20k n dBv -π ○11由①②④⑨○11得：12U U =Rd×nk n ππtan)2(4-≥1通过讨论：只有当k=1,n=3,4,5,6,7,8时，不等式成立. 所以，粒子与圆筒碰撞的可能次数为2，3，4，5，6，7.。

2018年武汉科技大学考研真题842大学物理A

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电荷线密度为，求环心处 O 点的电场强度.
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获得的能量是其静止能量的（
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2、（12 分）如图所示，长为l、质量为m的匀质杆可绕点
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广东工业大学物理下册试题

题号：309223010 分值：2 分难度系数等级：3 载流导线所产生的磁场与永磁体所产生的磁场具有不同的性质，所以在计算合磁场时，并不是总能进行叠加计算。（答：错）
3. 填空题
题号：30931001 分值：3 分难度系数等级：1 一根长直载流导线，通过的电流为 2A，在距离其 2mm 处的磁感应强度为（ 0 4 10 Tm/A）答： 2 10 4 T

（A） B 0 ，因为 B1 B 2 B3 0 （B） B 0 ，因为虽然 B1 0 ， B2 0 ，但 B1 B2 0 ， B3 0

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题号：30914014 分值：3 分难度系数等级：4
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答案：D
题号：30913018 分值：3 分难度系数等级：3 两条长导线相互平行放置于真空中，如图所示，两条导线的电流为 I 1 I 2 I ，两条导线到 P 点的距离都是 a，P 点的磁感应强度方向
（A）竖直向上
（B）竖直向下
（C）水平向右
（D）水平向左 [ ]