《高中物理選修3-1第二章 第三節(jié) 歐姆定律》教學(xué)設(shè)計(jì)

1、XXX Township people's Congress in support of the county people's Congress the Bureau, under the correct leadership of the party committees, in accordance with the responsibilities conferred by law, work closely around the Township as a whole, in accordance with the work plan developed by the

2、 beginning, methodically solid efforts. Now will work carried out situation be reported: a, and early main work (a) Xiang NPC construction work 1, and strengthening system construction, active carried out activities Xiang representative activities center, and representative group room established 8

3、items representative activities system: that NPC representative learning system, and representative co-voters system, and representative reception voters system, and representative debriefing system, and representative inspections system, and representative special research system, and representativ

4、e shoe vocational archives registration system and representative rushed out to excellence system. Each representative voters of not less than 10. Contact key village, the old Communist Party members, SHC, Petitions, and listening to their opinions and voices of effort when the masses of "voice

5、". 2, strengthen training, improve the ability of representatives duties duties is a matter of the people's Congress representative work is good or bad, therefore, improve the quality of representatives is particularly important. To improve the level of representatives of business, strength

6、ening the duty of representatives, establish a regular system of township people's Congress activities, organizations in the Conference room every Monday for collective learning, enhancing legal knowledge and service skills of the masses, so that each representative intellectually to the NPC dep

7、uties ' important duties and tasks for the next NPC's work laid the ideological and theoretical basis. 3, and carried out "double joint three race" activities, body people, solutions as their for in-depth implement implementation party of mass line education practice activities, XX

8、X Xiang NPC representative in "double joint three race" activities in the through NPC Bureau contact representative, and representative contact voters, to "visit, and listening to, and help" of form in-depth to masses in the to, understand people, solution as their, striving for

9、advanced Township NPC Bureau, and striving for advanced representative group, and race do excellent NPC representative. One is "visited" the masses. County and township people's Congress villages, understand what the masses think, hope. Officers insisted on home visits of 10 days a mon

10、th, general household visits for more than 6 days a month, first learn, problem solve, and duties in the first show. Second is "listen" to the public. Set up boxes, such as the opinions of the masses through meetings or solicited the opinions of the masses, the masses put forward the maint

11、enance of roads, ponds, bridges, dams, and transparent knowledge of agricultural science and technology to the countryside, poverty reduction and other livelihood views collection and solve them one by one. Third is "helping" people. According to what they need and seek, asked the Bureau m

12、embers each year to help people complete 1-2 projects, targeted help from 2 to 3 people, for helping the masses to do at least 1 things every month. Real mass education practice do actually, doing fine, well, the Township people's Congress work to a new level. 4, carried out on behalf of voters

13、report work progress programme by the Township people's Congress to voters, and 5 representatives of debriefing in the constituency on behalf of. Number of directly elected district representatives of participating voters of not less than 50% of the total voters, rural constituency representatio

14、n of voters of not less than 10% of the total number of voters, and the課題高中物理選修3-1第二章 第三節(jié) 歐姆定律 （1課時(shí)）作者及工作單位 藍(lán)娟 廣西英華國(guó)際職業(yè)學(xué)院附屬中學(xué)教材分析本節(jié)教材內(nèi)容涉及兩個(gè)問(wèn)題。一是歐姆定律，二是導(dǎo)體的伏安特性曲線。關(guān)于歐姆定律，教科書(shū)先用演示實(shí)驗(yàn)探究導(dǎo)體中電流與電壓的關(guān)系，通過(guò)U-I圖像處理的方法得到電流與電壓的正比關(guān)系，由斜率反映了導(dǎo)體對(duì)電流的阻礙作用，然后定義電阻。在此基礎(chǔ)上，通過(guò)對(duì)因果關(guān)系、適用條件的分析等，得到歐姆定律的公式及表述。這樣安排，在實(shí)驗(yàn)電路、數(shù)據(jù)處理、研究思

15、路等方面都較初中有很大提高，也更加科學(xué)。對(duì)導(dǎo)體伏安特性曲線的研究，尤其是測(cè)繪小燈泡伏安特性曲線的實(shí)驗(yàn)，使學(xué)生對(duì)歐姆定律的認(rèn)識(shí)更加深化。同時(shí)小燈泡的伏安特性曲線實(shí)驗(yàn)對(duì)第六節(jié)電阻的學(xué)習(xí)做好鋪墊，所以這個(gè)知識(shí)點(diǎn)既是本節(jié)課的重點(diǎn)也是難點(diǎn)。學(xué)情分析在初中學(xué)生已經(jīng)學(xué)習(xí)了歐姆定律，對(duì)歐姆定律已有一定的認(rèn)識(shí)，本節(jié)課要讓學(xué)生對(duì)歐姆定律有一個(gè)更多、更深層次的認(rèn)識(shí)。學(xué)生的好奇心很強(qiáng)，對(duì)物理實(shí)驗(yàn)很感興趣，但是學(xué)生的動(dòng)手能力不強(qiáng)，在演示實(shí)驗(yàn)部分和理論講解部分要加強(qiáng)師生的互動(dòng)性，調(diào)動(dòng)學(xué)生的積極性。另外，本節(jié)課當(dāng)中要用到圖像法，學(xué)生對(duì)圖像的分析比較薄弱，因此要有針對(duì)性的對(duì)學(xué)生進(jìn)行引導(dǎo)。教學(xué)目標(biāo)知識(shí)與技能：1.理解電阻的概念

16、，明確導(dǎo)體的電阻是由導(dǎo)體本身的特性所決定。2.要求學(xué)生理解歐姆定律，并能用來(lái)解決電路的問(wèn)題。3.知道導(dǎo)體的伏安特性曲線，知道什么是線性元件和非線性元件。過(guò)程與方法：1、通過(guò)演示實(shí)驗(yàn)知道電流的大小的決定因素，培養(yǎng)學(xué)生的實(shí)驗(yàn)觀察能力。 2、對(duì)實(shí)驗(yàn)數(shù)據(jù)用圖像法處理，培養(yǎng)學(xué)生邏輯推理、歸納總結(jié)的能力。情感、態(tài)度與價(jià)值觀：1、通過(guò)介紹歐姆的生平，以及“歐姆定律”的建立，激發(fā)學(xué)生的創(chuàng)新意識(shí)，培養(yǎng)學(xué)生在逆境中戰(zhàn)勝困難的堅(jiān)強(qiáng)性格。 2、培養(yǎng)學(xué)生善于動(dòng)手、勤于動(dòng)腦以及規(guī)范操作的良好實(shí)驗(yàn)素質(zhì)，培養(yǎng)學(xué)生仔細(xì)觀察認(rèn)真分析的科學(xué)態(tài)度。 教學(xué)重點(diǎn)和難點(diǎn)教學(xué)重點(diǎn)：1、歐姆定律的內(nèi)容、表達(dá)式及適用條件。 2、會(huì)用姆

17、定律分析解決一些實(shí)際問(wèn)題。 3、會(huì)用實(shí)驗(yàn)方法測(cè)繪導(dǎo)體的伏安特性曲線。教學(xué)難點(diǎn)：1、根據(jù)電路圖會(huì)實(shí)物圖的連接，或根據(jù)實(shí)物圖的連接會(huì)畫(huà)路圖。2、理解伏安特性曲線的物理意義。教具學(xué)生電源、電壓表、電流表和滑動(dòng)變阻器各一只，5、10的定值電阻各一只，小燈泡各一個(gè)，開(kāi)關(guān)一個(gè)，導(dǎo)線若干。教學(xué)流程圖開(kāi)始結(jié)束創(chuàng)設(shè)情境，引入課題歐姆定律、伏安特性曲線分析論證，得出結(jié)論設(shè)計(jì)實(shí)驗(yàn)，進(jìn)行實(shí)驗(yàn)猜想假設(shè)提出問(wèn)題展示學(xué)習(xí)目標(biāo)課堂小結(jié)，當(dāng)堂檢測(cè)教學(xué)過(guò)程教學(xué)環(huán)節(jié)教師活動(dòng)預(yù)設(shè)學(xué)生行為設(shè)計(jì)意圖 一、展示學(xué)習(xí)目標(biāo)（30秒）展示學(xué)習(xí)目標(biāo)大聲朗讀本節(jié)課學(xué)習(xí)目標(biāo)利用多媒體展示這節(jié)課的目標(biāo)和要求，讓學(xué)生有目的地進(jìn)行學(xué)習(xí)，做到有的放

18、矢。二、情境導(dǎo)入（2分鐘）三、新課學(xué)習(xí)，合作探究（30分鐘）AVRESL 提出問(wèn)題：什么是電流？電路中形成電流的原因是什么？鼓勵(lì)學(xué)生大膽猜想：電流的變化可能與哪些因素有關(guān)？電荷的定向移動(dòng)形成電流觀察現(xiàn)象，思考回答（電壓變化導(dǎo)致電流變化）觀察現(xiàn)象，思考回答（電阻變化導(dǎo)致電流變化） 猜想假設(shè)：導(dǎo)體中的電流I與加在導(dǎo)體兩端的電壓U成正比，與導(dǎo)體的電阻R成反比。從實(shí)驗(yàn)現(xiàn)象中提出問(wèn)題，讓學(xué)生感受到物理來(lái)源于生活并作用于生活，并且激發(fā)學(xué)生學(xué)習(xí)物理的興趣和熱情，同時(shí)為探究歐姆定律創(chuàng)設(shè)情境。對(duì)每一個(gè)學(xué)生的猜想給予鼓勵(lì)，讓學(xué)生體會(huì)到成功的幸福感。1、設(shè)計(jì)實(shí)驗(yàn)（1分鐘）啟發(fā)和引導(dǎo)學(xué)生計(jì)研究解決問(wèn)題的方案

19、，應(yīng)用控制變量法設(shè)計(jì)總體方案。1.控制電阻R不變，探究電流I與電壓U的關(guān)系；2.控制電壓U不變，探究電流I與電阻R的關(guān)系。初步理解電流、電壓、電阻的關(guān)系，進(jìn)一步體會(huì)控制變量法。2、評(píng)估方案的可行性，進(jìn)一步優(yōu)化（4分鐘）投影討論題：保持電阻不變，探究電流與電壓的關(guān)系時(shí)，如何改變電壓？電壓和電流用什么儀器測(cè)量？保持電壓不變，探究電流與電阻的關(guān)系時(shí)，如何讓控制電壓不變？本實(shí)驗(yàn)采用什么電路圖？各儀表采用的量程多大？設(shè)計(jì)怎樣的實(shí)驗(yàn)數(shù)據(jù)記錄表格？介紹分壓法測(cè)電阻的實(shí)驗(yàn)電路圖的優(yōu)點(diǎn)。實(shí)驗(yàn)電路圖：思考討論，積極回到問(wèn)題。根據(jù)實(shí)驗(yàn)原理和電路圖選擇所需的實(shí)驗(yàn)器材：學(xué)生電源、電壓表、電流表和滑動(dòng)變阻器各一只，5、1

20、0的定值電阻各一只，一個(gè)開(kāi)關(guān)，導(dǎo)線若干。U/vIA/AIB/A00.511.522.53通過(guò)自己設(shè)計(jì)電路培養(yǎng)繪圖能力.培養(yǎng)學(xué)生嚴(yán)謹(jǐn)認(rèn)真的科學(xué)態(tài)度以提示、點(diǎn)撥為主，以一系列問(wèn)題，逐步深入，啟發(fā)學(xué)生思維，引導(dǎo)思考的方向,控制變量法的思維探究問(wèn)題。授人以漁，物理方法教學(xué)。培養(yǎng)學(xué)生的學(xué)習(xí)能力，使學(xué)生由學(xué)會(huì)轉(zhuǎn)變?yōu)闀?huì)學(xué)；同時(shí)在教師給出的提綱的引領(lǐng)下，抓住重點(diǎn)，提高課堂的學(xué)習(xí)效率。3、分組實(shí)驗(yàn)，記錄數(shù)據(jù)（4分鐘）4、分析論證，得出結(jié)論（2分鐘）教師在學(xué)生操作技能、儀器使用上給予幫助。從實(shí)驗(yàn)得出的兩組數(shù)據(jù)引導(dǎo)，讓學(xué)生自己發(fā)現(xiàn)規(guī)律，得出結(jié)論。 收集數(shù)據(jù)等活動(dòng)來(lái)實(shí)施方案。使用圖像法總結(jié)規(guī)律：將實(shí)驗(yàn)數(shù)據(jù)描到以下坐標(biāo)

21、系中，觀察并分析得出實(shí)驗(yàn)結(jié)論。培養(yǎng)動(dòng)手操作能力，通過(guò)實(shí)驗(yàn)培養(yǎng)合作探究意識(shí)。培養(yǎng)觀察分析能力，語(yǔ)言表達(dá)能力，根據(jù)現(xiàn)象總結(jié)概括能力。培養(yǎng)學(xué)生實(shí)事求是的科學(xué)態(tài)度，能對(duì)實(shí)驗(yàn)進(jìn)行正確評(píng)價(jià)。知識(shí)點(diǎn)1、電阻（4分鐘）師生互動(dòng)，利用比值定義法得出電阻的概念：電壓和電流的比值R=，反映了導(dǎo)體對(duì)電流的阻礙作用，叫做導(dǎo)體的電阻。R的大小與U、I無(wú)關(guān)，只有本身決定。通過(guò)比值定義法來(lái)定義電阻，比初中更科學(xué)和合理，更能讓學(xué)生接受這個(gè)物理量。知識(shí)點(diǎn)2、歐姆定律（5分鐘）引導(dǎo)學(xué)生將上式變形得I=介紹德國(guó)物理學(xué)家歐姆和歐姆定律的建立將上式變形得I=用文字表述：導(dǎo)體中的電流跟導(dǎo)體兩端的電壓成正比，跟導(dǎo)體的電阻成反比。了解歐姆的探

22、究背景，體會(huì)科學(xué)家的艱辛和執(zhí)著，以及一個(gè)定理的來(lái)之不易。培養(yǎng)學(xué)生數(shù)學(xué)變形能力，語(yǔ)言表達(dá)能力，歸納總結(jié)的能力。使學(xué)生感受成功背后的艱辛，培養(yǎng)學(xué)生堅(jiān)韌不拔的意志。典例分析，學(xué)以致用（2分鐘）引導(dǎo)：歐姆定律在現(xiàn)實(shí)生活中有什么意義呢？例1、為什么電流表不允許直接接在電源兩極上，而電壓表卻可以？例2、某一電阻接在40伏的電路中，其上通過(guò)的電流為2安，問(wèn)：該電阻為大？若電壓增大到80伏時(shí)，其電阻為多大？電流是多大？認(rèn)真思考，回答問(wèn)題根據(jù)歐姆定律解釋說(shuō)明，體會(huì)電流、與電阻的關(guān)系，利用歐姆定律解決實(shí)際問(wèn)題，一學(xué)生在黑板解答，其余的在座位解答。培養(yǎng)利用所學(xué)知識(shí)分析解決實(shí)際問(wèn)題的能力。進(jìn)一步理解電阻是導(dǎo)體本身的一

23、種性質(zhì)。深化理解歐姆定律的內(nèi)涵。知識(shí)點(diǎn)3、導(dǎo)體的伏安特性曲線（4分鐘）介紹伏安特性曲線和線性元件。出示問(wèn)題，引導(dǎo)學(xué)生思考：在IU曲線中，圖線的斜率表示的物理意義是什么？思考討論、總結(jié)：在IU圖中，圖線的斜率表示導(dǎo)體電阻的倒數(shù)。即k=。圖線的斜率越大，電阻越小。培養(yǎng)學(xué)生應(yīng)用數(shù)學(xué)知識(shí)解決物理問(wèn)題的能力，培養(yǎng)學(xué)生掌握通過(guò)圖像獲取有用信息的能力.知識(shí)點(diǎn)4、實(shí)驗(yàn)：小燈泡的伏安特性曲線（4分鐘）探究實(shí)驗(yàn)：描繪小燈泡的伏安特性曲線，指導(dǎo)學(xué)生做好實(shí)驗(yàn)，記錄數(shù)據(jù)，描點(diǎn)畫(huà)圖。引導(dǎo)學(xué)生思考：小燈泡的伏安特性曲線，說(shuō)明了什么問(wèn)題？思考討論，得出結(jié)論：小燈泡的伏安特性曲線不是一條過(guò)原點(diǎn)的直線，說(shuō)明小燈泡不是線性元件，是

24、非線性元件。且電阻隨溫度的升高而增大。通過(guò)對(duì)生活中熟悉的小燈泡作為研究對(duì)象，可以激發(fā)學(xué)生的好奇心和求知欲望。對(duì)圖像的分析，得出結(jié)論，培養(yǎng)學(xué)生利用已有知識(shí)解決問(wèn)題的能力，使學(xué)生對(duì)歐姆定律的認(rèn)識(shí)更加深化。從而更好的理解“非線性元件”的定義。典例分析，學(xué)以致用（1分鐘）例題3、兩電阻R1、R2的伏安特性曲線如圖所示，由圖可知：這兩電阻的大小之比R1R2為_(kāi)A.13B.31C.1D.1根據(jù)I-U圖像，斜率表示導(dǎo)體電阻的倒數(shù)。即k=來(lái)求解。進(jìn)一步加深學(xué)生對(duì)導(dǎo)體的伏安特性曲線的理解。 四、課堂小結(jié) （2分鐘） 板書(shū)設(shè)計(jì)第三章 第二節(jié) 歐姆定律一、電阻（R）1、物理意義：反映導(dǎo)體對(duì)電流的阻礙作用2、定義：導(dǎo)

25、體兩端的電壓與通過(guò)導(dǎo)體的電流的比值3、定義式：R=U/R4、單位：歐姆（）二、歐姆定律1、內(nèi)容：導(dǎo)體中的電流I 跟導(dǎo)體兩端的電壓U成正比,跟導(dǎo)體的電阻R成反比2、公式：I=U/R3、適用條件：金屬導(dǎo)體和電解液導(dǎo)體，而對(duì)汽態(tài)導(dǎo)體和半導(dǎo)體不適用三、導(dǎo)體的伏安特性曲線1、定義：用縱軸表示電流I，用橫軸表示電壓U，畫(huà)出的IU圖線叫做導(dǎo)體的伏安特性曲線。2、線性元件和非線性元件當(dāng)堂檢測(cè)（5分鐘）1、根據(jù)歐姆定律，下列說(shuō)法中正確的是（ ）A從關(guān)系式R=U/I可知，對(duì)于一個(gè)確定的導(dǎo)體來(lái)說(shuō)，如果通過(guò)的電流越大，則導(dǎo)體兩端的電壓也越大B從關(guān)系式R=U/I可知，導(dǎo)體的電阻跟導(dǎo)體兩端的電壓成正比，跟導(dǎo)體中的電流成正

26、比C從關(guān)系式I=U/R可知，導(dǎo)體中的電流跟導(dǎo)體兩端的電壓成正比，跟導(dǎo)體的電阻成反比D從關(guān)系式R=U/I可知，對(duì)于一個(gè)確定的導(dǎo)體來(lái)說(shuō)，所加在的電壓跟通過(guò)的電流的比值是一確定值 2、鳥(niǎo)落在110kv的高壓輸電線上，雖然通電的高壓線是祼露的確電線，但鳥(niǎo)仍然安然無(wú)恙，這是因?yàn)椋?）A鳥(niǎo)有耐高壓的天性B鳥(niǎo)腳是干燥的，所以鳥(niǎo)體不導(dǎo)電C鳥(niǎo)兩腳間的電壓幾乎為零D鳥(niǎo)體電阻極大，所以無(wú)電流通過(guò)3、一段導(dǎo)體兩端電壓是4v，在2 min內(nèi)通過(guò)導(dǎo)體某一橫截面面積的電荷量是15C，那么這段導(dǎo)體的電阻應(yīng)為 4、有三個(gè)電阻，RA=5，RB=10，RC=2.5,它們的伏安特性呈線性特征，請(qǐng)?jiān)谕蛔鴺?biāo)系中作出它們的伏安

27、特性曲線，并在線旁標(biāo)明A、B、C。課后作業(yè)：書(shū)面完成P48“問(wèn)題與練習(xí)”第2、3、4、題；思考并回答第1、5題。教學(xué)反思成功之處：1.引入中能夠充分調(diào)動(dòng)學(xué)生學(xué)習(xí)的積極性、主動(dòng)性，激發(fā)學(xué)生的探究欲望，為本節(jié)課的順利教學(xué)做好了準(zhǔn)備。2.通過(guò)比較完整的實(shí)驗(yàn)探究過(guò)程，讓學(xué)生體會(huì)科學(xué)的探究方法，培養(yǎng)科學(xué)探究的能力，為學(xué)生的終身發(fā)展打基礎(chǔ)。3.本節(jié)課的實(shí)驗(yàn)數(shù)據(jù)是總結(jié)歐姆定律的基礎(chǔ)，通過(guò)分組探究活動(dòng)，使學(xué)生能夠積極地投入到課堂的學(xué)習(xí)中去，熱情很高。實(shí)驗(yàn)取得的數(shù)據(jù)多數(shù)較好，為歐姆定律的得出奠定了很好的條件。4.充分利用多媒體實(shí)物展臺(tái)，為學(xué)生搭建了一個(gè)展示自己的平臺(tái)，增強(qiáng)了學(xué)生的自信心，體會(huì)到學(xué)習(xí)的樂(lè)趣。這也是

28、本節(jié)教學(xué)最大的亮點(diǎn)。整堂課融基礎(chǔ)性、靈活性、實(shí)踐性、開(kāi)放性于一體。這樣既注重知識(shí)的發(fā)生、發(fā)展、形成的過(guò)程，又通過(guò)探索過(guò)程，不斷提高解決問(wèn)題的能力，滲透物理的思想方法，發(fā)展物理思維。不足之處：由于本節(jié)課容量大，內(nèi)容多，課堂的例題相對(duì)比較簡(jiǎn)單，導(dǎo)致學(xué)生對(duì)歐姆定律和伏安特性曲線理解不夠到位，習(xí)題課應(yīng)加強(qiáng)。Whether they have health certificates, school and shop around if there is "three noes" of food and other check point. Meanwhile, representat

29、ive to inspect the campus surrounding environment, relevant departments banned three illegal construction around the campus by two points. And few schools fire equipment is missing, mine infrastructure, security hardware is not enough, bad traffic and poor sanitation made four recommendations. A is

30、to strictly attention campus environment health management; II is to further perfect school of fire facilities, and fire evacuation channel, and teaching floor emergency lighting lamp, and evacuation led and anti-mine facilities, and established striking logo brand; three is to strengthening on elem

31、entary and middle school students public security common sense publicity and education, set security consciousness, training strain capacity; four is to sound security management institutions, implementation security emergency programme, implementation responsibility held business. 3, the constructi

32、on of the new rural community inspections in May this year, XXX held Township people's Congress meetings of the Bureau, Xiang Li, XXX Park community building, macro-community planning, water, electricity, roads and public facilities; square, Park and community green comprehensive inspections. Co

33、mprehensive assessment and community building. Final community plan: 3 River viaduct, River Road 2, built within the community will form a "four vertical and four horizontal" structure, best facilitate the everyday life of the masses. The community building carried out in 8 years in three

34、phases, the first phase of construction with 6.7 hectares of land, demolishing old integration after use, legitimate 14.4-hectare, expected to be completed by 2015; the second phase demolishing old and new carried out in three years, and the end of 2018; the third phase to be completed by the end of

35、 2020. Currently works smoothly and is completed, it will be XXX Shan boutique livable communities. 4, reflecting people's Congress functions, pays special attention to the NPC petition work XXX work of letters and calls Bureau of the NPC has always attached importance to people's Congress.

36、A serious study, improve professional quality. 18 the spirit of the party as an opportunity to request comprehensively improve the overall quality of the members of the Bureau on the basis of conscientious study of the complaint reporting handling Office Ordinance, the supervision law, land management law and other laws and regulations closely related to rural people. Se