Chương 4: TỪ TRƯỜNG I. HỆ THỐNG KIẾN THỨC TRONG CHƯƠNG 1. Từ trường. Cảm ứng từ - Xung quanh nam châm và xung quanh dòng điện từ trường. Từ trường có tính chất cơ bản là tác dụng lực từ lên nam châm hay lên dòng điện đặt trong nó.tồn tại - Vectơ cảm ứng từ là đại lượng đặc trưng cho từ trường về mặt tác dụng lực từ. Đơn vị cảm ứng từ là Tesla (T). - Từ trường của dòng điện trong dây dẫn thẳng, dài đặt trong không khí: r I 10.2B 7− = r là khoảng cách từ điểm khảo sát đến dây dẫn. - Từ trường tại tâm của dòng điện trong khung dây tròn: R NI 10.2B 7− π= R là bán kính của khung dây, N là số vòng dây trong khung, I là cường độ dòng điện trong mỗi vòng. - Từ trường của dòng điện trong ống dây: nI10.4B 7− π= n là số vòng dây trên một đơn vị dài của ống. 2. Lực từ - Lực từ tác dụng lên một đoạn dòng điện ngắn: F = Bilsinỏ ỏ là góc hợp bởi đoạn dòng điện và vectơ cảm ứng từ. - Lực từ tác dụng trên mỗi đơn vị dài của hai dòng điện song song: r II 10.2F 21 7− = r là khoảng cách giữa hai dòng điện. 3. Mômen ngẫu lực từ: Mômen ngẫu lực từ tác dụng lên khung dây có dòng điện: M = IBS.sinố, trong đó S là diện tích phần mặt phẳng giới hạn bởi khung, ố là góc hợp bởi vectơ pháp tuyến của khung và vectơ cảm ứng từ 4. Lực Lorenxơ: Lực Lorenxơ tác dụng lên hạt mang điện chuyển động: α= sinBvqf , trong đó q là điện tích của hạt, ỏ là góc hợp bởi vectơ vận tốc của hạt và vectơ cảm ứng từ II. CÂU HỎI VÀ BÀI TẬP 1. Từ trường 4.1 Phát biểu nào sau đây là không đúng? Người ta nhận ra từ trường tồn tại xung quanh dây dẫn mang dòng điện vì: A. có lực tác dụng lên một dòng điện khác đặt song song cạnh nó B. có lực tác dụng lên một kim nam châm đặt song song cạnh nó C. có lực tác dụng lên một hạt mang điện chuyển động dọc theo nó D. có lực tác dụng lên một hạt mang điện đứng yên đặt bên cạnh nó. 4.2 Tính chất cơ bản của từ trường là: A. gây ra lực từ tác dụng lên nam châm hoặc lên dòng điện đặt trong nó. B. gây ra lực hấp dẫn lên các vật đặt trong nó C. gây ra lực đàn hồi tác dụng lên các dòng điện và nam châm đặt trong nó D. gây ra sự biến đổi về tính chất điện của môi trường xung quanh 4.3 Từ phổ là: A. hình ảnh của các đường mạt sắt cho ta hình ảnh của các đường sức từ của từ trường. B. hình ảnh tương tác của hai nam châm với nhau 1 C. hình ảnh tương tác giữa dòng điện và nam châm D. hình ảnh tương tác của hai dòng điện chạy trong hai dây dẫn thẳng song song 4.4 Phát biểu nào sau đây là không đúng? A. Qua bất kỳ điểm nào trong từ trường ta cũng có thể vẽ được một đường sức từ B. Đường sức từ do nam châm thẳng tạo ra xung quanh nó là những đường thẳng. C. Đường sức mau ở nơi có cảm ứng từ lớn, đường sức thưa ở nơi có cảm ứng từ nhỏ D. Các đường sức từ là những đường cong kín 4.5 Phát biểu nào sau đây là không đúng? Từ trường đều là từ trường có A. các đường sức song song và cách đều nhau B. cảm ứng từ tại mọi nơi đều bằng nhau C. lực từ tác dụng lên các dòng điện như nhau. D. các đặc điểm bao gồm cả phương án A và B 4.6 Phát biểu nào sau đây là không đúng? A. Tương tác giữa hai dòng điện là tương tác từ B. Cảm ứng từ là đại lượng đặc trưng cho từ trường về mặt gây ra tác dụng từ C. Xung quanh mỗi điện tích đứng yên tồn tại điện trường và từ trường. D. Đi qua mỗi điểm trong từ trường chỉ có một đường sức từ 4.7 Phát biểu nào sau đây là đúng? A. Các đường mạt sắt của từ phổ chính là các đường sức từ B. Các đường sức từ của từ trường đều có thể là những đường cong cách đều nhau C. Các đường sức từ luôn là những đường cong kín. D. Một hạt mang điện chuyển động theo quỹ đạo tròn trong từ trường thì quỹ đạo chuyển động của hạt chính là một đường sức từ 4.8 Dây dẫn mang dòng điện không tương tác với A. các điện tích chuyển động B. nam châm đứng yên C. các điện tích đứng yên. D. nam châm chuyển động 2. Phương và chiều của lực từ tác dụng lên dòng điện 4.9 Phát biểu nào sau đây là đúng? Một dòng điện đặt trong từ trường vuông góc với đường sức từ, chiều của lực từ tác dụng vào dòng điện sẽ không thay đổi khi A. đổi chiều VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí TEST YOURSELF B TEST Choose the word which is stressed differently from the rest a generally b secondary c education d specialize a particular b variety c certificate d supplementary a equivalent b independent c university d entertainment a intensive b requirement c usually d assessment a common b exam c degree d prepare Choose a, b, c, or d that best completes each unfinished sentence, substitutes the underlined part, or has a close meaning to the original one An 'A-level' in Mathematics or a/ an _ qualification, is normally required a equal c equivalent b same d like At the age of sixteen he for a place at the University of Harvard a expected b submitted d qualified c required GCSEs are often a requirement for taking A-levels, a common type of university _ requirement a entrance b enclose c attendance d assessment GCSE courses are _ in a variety of subjects, which are usually decided by the students themselves a spent b taken c made d looked 10 GCSEs are not compulsory, but they are the most common qualification taken by 14-16-year-old students a specialized c required b fulfilled d applied 11 Secondary education is the _ of education following primary school a stage b step c level d standard 12 Then he'll know exactly what's required _ him a of b in c with d for 13 That language center has a wide variety _ subjects for you to choose a at c of b upon d about 14 I admired him for being so confident _ his age a for b at c In d on 15 She is a slow student She seems to be unable to concentrate on anything in _ a particular b particularly c particularity d particularize 16 You should find a job to live _ from your parents a dependence b independence c independent d independently VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí 17 Those who well on the test clearly have the _ fluency a require b requirement c requisite d requiring 18 Most _ students in _ UK prepare carefully for A-level exams b Ø / the a the / Ø c Ø / an d the / an 19 Where is Peter? - He is at _ school a a b an d Ø c the 20 _ with my previous job, I would have won a higher promotion and I _ in this unfortunate position now a Unless I had stayed I am not c If had I stayed / will not be b If I stayed / would not be d Had I stayed / would not be 21 If they _ down that old opera house, we would not have any historical architecture left in the city a tear b tore c torn d were torn 22 I can't stand him If he _, I will quit a is employed b employed c were employed d had employed 23 Without my parents' support, I _ my overseas study a will not complete b did not complete d would not have completed c had not completed 24 _ at home, I would enjoy my favourite show a Suppose I am b Unless were I c Were I d If were I 25 The man and his dogs _ were buried in the demolished building after the earthquake have just been rescued safely a which b who c that d whom 26 Since the global industrialization, the number of animal species _ have become extinct or nearly extinct has increased a which b when c why d whose 27 Of my students, Betty is the only one _ has found a good job b that a where c which d whose 28 Have you ever visited New York harbor _ the famous Statue of Liberty stands? a on where b that c on that d where 29 Tell me the day _ you want to leave a which b when c in that d where 30 That is the place _ there used to be a monument a where Error Identification b that c why d for which VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí 31 The General Certificate of Secondary Education (GCSE) is the name of A a set of English qualifications, generally taking by secondary school B C (taken) students at the age of 15-16 in England D 32 When GCSEs are taken' in secondary school, they can often combined A B with other qualifications, or diplomas (be combined) C D 33 If you decide to take any examination system, you should make contact A B with the Admissions Office to ask for an appropriate preparation for the subject whom you are planning to study (which / that) C D 34 Entry standards at Cambridge University require students who have A B C studied to the highest level available for school students, and having achieved top grades D (have) 35 If you have already decided on a course that you would like to study at A B university, or we recommend that you take a look at the course C (we) requirements first D Read the two passages carefully and choose the correct answer There is no age requirement for admission to Cambridge University, although the vast majority of undergraduates are 18 years' or older when they come into residence All applicants will need to demonstrate that they have the maturity and personal skills to cope with university level study A student who will be over 21 on commencing a course is classified as a mature student VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí In previous years, the ... Co Loa high school The 1 st test of the first term English 12 Time allowance : 45 minutes English Test (M· ®Ò 116) C©u 1 : 27. The word “verbalization” probably means _________. A. picture signs B. signal flags C. body language D. expression in words C©u 2 : Choose one word in each group that has the underlined part pronounced differently from the rest. A. dates B. photographs C. speaks D. kids C©u 3 : The report has not be examined by the committee of experts yet. A. has not be examined B. by C. committee D. yet C©u 4 : Over 1500 new houses _______ each year. Last year, 1720 new houses ____ A. are built/ were built B. were built/ were built C. were built/ were being built D. are building/ were built C©u 5 : This passage mainly tells us that ________. A. everybody uses only one form of communication B. people can make themselves understood in different ways C. non-linguistic language is invaluable to foreigners D. oral speech is the fastest form of communication C©u 6 : Peter is said being good at English. A. is said B. being C. good D. at C©u 7 : I _______this film twice. A. saw B. have seen C. will see D. see C©u 8 : Which of the following statements is NOT true? A. There are many forms of communication in existence today. B. Ideas and thoughts can be expressed by body language. C. Everyone can use an oral form of communication. D. Blind people can communicate with each other in Braille. C©u 9 : Choose one word in each group that has the underlined part pronounced differently from the rest. A. helped B. asked C. shared D. laughed C©u 10 : Mr. John_______ to Los Angeles in 1992. A. was going B. had gone C. has gone D. went C©u 11 : Tom bought that book yesterday. A. That book was bought yesterday by Tom B. That book was bought by Tom yesterday C. That book was bought yesterday D. That book yesterday was bought by Tom C©u 12 : Don't forget to say goodbye to the before leaving the office. A. interviewing B. interviewee C. interview D. interviewer C©u 13 : “Can I borrow your pen please, Sam?”, said Gillian. A. Gillian asked Sam she can borrow his pen. B. Gillian asked Sam if she can borrow his pen. C. Gillian asked Sam if she could borrow his pen. D. Gillian asked Sam she could borrow his pen. C©u 14 : 'You'd better look for a new job, Andrew.' A. Jane advised to look for a new job. B. Jane advised looking for a new job, Andrew. C. Jane advised Andrew to look for a new job. D. Jane advised Andrew look for a new job. C©u 15 : Which of the following is used by most people around the world? A. Verbal language B. Sign language C. Braille D. Smoke signals C©u 16 : “What were you doing last night, Mr. John?” The police asked. A. The police asked Mr. John what he had been doing the night before. 1 B. The police asked Mr. John what he had done the night before. C. The police asked what were you doing last night, Mr. John. D. The police asked Mr. John what had he been done the night before. C©u 17 : Choose a word in each line that has different stress pattern. A. sacrifice B. compliment C. argument D. apologize C©u 18 : She said to us “Don’t be late again”. A. She told to us not to be late again. B. She told us not to be late again. C. She said us not to be late again. D. She told us to be not late again. C©u 19 : She _____ English before she came to England. A. studies B. would study C. had studied D. studied C©u 20 : He is very brave. His friends are impresses by his bravery. A. brave B. His friends C. are impresses D. bravery C©u 21 : Choose a word in each line that has different stress pattern. A. contractual B. counterpart C. biologist D. suppotive C©u 22 : Choose one word in each group that has the underlined part pronounced differently from the rest. A. phoned B. arrived C. explained D. decided C©u 23 : It was nice of you to invite me to your birthday party. Thanks very much. A. Mike thanked me for to invite him to my birthday party. B. Mike VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí UNIT 4: AT SCHOOL Welcome to English 7 BÀI GIẢNG ĐIỆN TỬ WRITE THE TIME IN WORDS + 7.10 + 8.00 + 9.00 + 9.50 + 10.40 + 11.25 + seven ten / ten past seven + eight o’clock + nine o’clock + nine fifty / ten to ten + ten forty / twenty to eleven + eleven twenty five / twenty five past eleven UNIT 4 : AT SCHOOL LESSON 1: A1,2,3 /P 42-43 a. It’s five twenty five. b. It’s one forty- five. c. It’s seven o’clock. d. It’s eight thirty. e. It’s four fifteen. f. It’s nine forty. g. It’s a quarter past four. h. It’s half past eight. i, It’s twenty- five past five. k, It’s a quarter to two. l, It’s twenty to ten. 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 1 2 3 4 5 6 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 It’s seven o’clock. It’s four fifteen. It’s a quarter past four. It’s five twenty five. It’s twenty five past five. It’s eight thirty. It’s nine forty. It’s twenty to ten. It’s one forty- five. It’s a quarter to two. 1. Listen and repeat A1/p 42: 9 12 6 3 S1: What time is it? 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 9 12 6 3 S2: It’s seven o’clock. 9 12 6 3 1 2 3 4 5 6 * Saying the time: UNIT 4 : AT SCHOOL LESSON 1: A1,2,3 /P 42-43 2. Listen and write A3/p43: a. Subjects at school: - math - physics - biology - English - literature - history - geography - civic education - physical education - technology - art - music - toán - vật lí - sinh - tiếng Anh - văn - lịch sử` - địa lí - gdcd - thể dục - công nghệ - mĩ thuật - âm nhạc b. Complete the schedule: 7.00 8.40 10.30 geography physics Friday Friday 2.40 4.30 physical education English b. Complete the schedule: 7.00 7.50 8.40 9.40 10.30 English geography music physics history Friday Friday 1.00 2.40 3.40 4.30 physical education math English physics c. Questions: 1. How many subjects do you have at school? 2. How many classes do you have every morning? 3. What time do you have the first class? 4. What time do you have the second class? 5. What time do you have the third class? 6. What time do you have the fourth class? 7. What time do you have the fifth class? 8. What time do you finish your classes? 9. What time do you have recess? VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí Bài tập trắc nghiệm Tiếng Anh lớp Unit At School Bài 1: 3.45 is said :…… a It’s three to forty- five b It’s quarter to four c It’s quarter to three b It’s nine fifteen c It’s nine quarter b you go to bed c you go to bed 9.15 is said : … a It’s quarter to nine What time … ? a are you going to go to bed? What time does Hanh …in history class ? a study b have c learns b you study c you are studying What …… ? – Math a are you study ? Thi has Physics … Tuesday … 30 a on-at b from-to c at-on b This c These … racks have magazines a That Do you have magazines and … here ? a science book b newspapers c dictionary You can find Math books …the shelves … the left a on-on b on-at c in-on b library c engineer 10 Mrs Hoa is a … a librarian 11 English books are … the back … the library a on-of b at-of c in-of 12 … you have physical education ? a When b What time c How b What c Why 13 … I find a book , please? a How 14 You can find a book with either the author … the title a and b or 15 In the USA , students … a school uniform c about VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí a are not wearing b not wear c is not wearing b wears c is wearing 16 Hoa … a nice dress today a wear 17 What time is it ? - it … four fifteen a is b are c on 18 They put the chairs … the middle of the garden a in b at c on b play c plays 19 He learns … badminton a playing 20 In American , soccer is the usual word for … a volleyball b football c basketball Đáp án b 2.b 3.a 4.a 5.b a 7.c 8.b 9.a 10.a 11.c 12.a 13.a 14.b 15.b 16.c 17.a 18.a 19.a 20.b Bài 2: They … some snack at the moment a have b is having c having b fifteen c twenty It’s a quarter past five a ten English dictionaries are … the back of the library a in b at c on b library c stadium b on c in b will play c are playing b pasts c pass We go to the … to read books a cafeteria I usually get … early a up Look! They baseball ! a play It’s five … five a past He shelves on the … have math and science books a left b middle In physical Education, he learn … volleyball c back VnDoc - Tải tài liệu, văn pháp luật, biểu mẫu miễn phí a playing b play c to play 10 … is my favorite subject at school because I love animals and plants a Math b Biology c History b class c period 11 We have four today a classes 12 The class … at o’clock in the morning a start b starts c ends 13 … you go to bed ? – at half past ten a What b When c What time 14 … does Nga have history ? – On Monday and Thursday a When b What time c How long b with c from b 20- minute breaks c 20- minute break 15 He looks different … his father a at 16 Students have two … each day a 20- minutes breaks 17 The United States’ library of Congress is one of the … libraries in the world a larger b largest c larger than b This c that b please c pleasing 18 … novels are very interesting a These 19 I’m very … to see you here a pleased 20 Hurrah ! we’ll have a day this week a on b off Đáp án 1.b 2.b 3.b 4.a A 6.c 7.a 8.a 9.a 10.b 11.a 12.b 13.c 14.a 15.c 16.b 17.b 18.a 20.b c of UNIT 12 I. Make sentences as examples: Ex: Lan/ play badminton What is Lan doing? – She’s playing badminton. a. they/ swim ………………………………………………………………………………………………………………… ………………………………………………………………………………… b. Phong/ play soccer. ………………………………………………………………………………………………………………… ………………………………………………………………………………… c. Hoa and Mai/ play table tennis. ………………………………………………………………………………………………………………… ………………………………………………………………………………… d. the children/ play volleyball. ………………………………………………………………………………………………………………… ………………………………………………………………………………… e. Mr. Ba/ jog. ………………………………………………………………………………………………………………… ………………………………………………………………………………… f. the students/ play basketball. ………………………………………………………………………………………………………………… ………………………………………………………………………………… II. Finish the passage with the simple present or the present continuous (present progressive) form of the verbs in brackets. a. Mr. Ba likes jogging. He (jog) ……………………………… every day. He (jog) ……………………………… in the park now. b. Ba and Lan like chess. They (play) ……………………………… it every afternoon. They (play) ……………………………… chess in the living room at the moment. c. Phong and his classmates like soccer. They (play) ……………………………… it every Sunday. They (play) ……………………………… soccer in the schoolyard now. d. Hang always (do) ……………………………… aerobics in the morning. She (do) ……………………………… aerobics in the gym now. e. Hoa and Xuan like rope skipping. They (skip) ………………………………rope every afternoon. They (skip) ……………………………… rope in the garden at the moment. III. Make sentences. Ex: you/ play soccer Do you like sports? – Yes, I do. Which sports do you play? – I play soccer. a. Mai/ skip rope. ………………………………………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………………………………………… ………………………………………………………………………………… b. Hoa and Phong/ play table tennis. ………………………………………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………………………………………… ………………………………………………………………………………… c. Mr. Tuan/ jog. ………………………………………………………………………………………………………………… ………………………………………………………………………………… 1 ………………………………………………………………………………………………………………… ………………………………………………………………………………… d. your classmates/ basketball. ………………………………………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………………………………………… ………………………………………………………………………………… IV. Make sentences. Ex: Lan/ watch television. What does Lan do in her free time? – She watches television. a. you/ play video games. ………………………………………………………………………………………………………………… ………………………………………………………………………………… b. Lan/ listen to music. ………………………………………………………………………………………………………………… ………………………………………………………………………………… c. Mr. Ba’s children/ play chess. ………………………………………………………………………………………………………………… ………………………………………………………………………………… V. Make sentences. Ex: Lan/ watch television/ three times a week. How often does Lan watch television? - She watches television three times a week. a. you/ play video games/ twice a week. ………………………………………………………………………………………………………………… ………………………………………………………………………………… b. Lan/ go to the movies/ once a month. ………………………………………………………………………………………………………………… ………………………………………………………………………………… c. Mr. Ba’s children/ go to the zoo/ every Sunday. ………………………………………………………………………………………………………………… ………………………………………………………………………………… d. Phong/ go fishing/ every Saturday afternoon. ………………………………………………………………………………………………………………… ………………………………………………………………………………… VI. Make sentences. Ex: Lan/ go to school early/ always. How often does Lan go to school early? – She always goes to school early. a. you/ stay up late/ never ………………………………………………………………………………………………………………… ………………………………………………………………………………… b. Lan and Hoa/ skip rope in the garden/ sometimes. ………………………………………………………………………………………………………………… ………………………………………………………………………………… c. Mr. Ba’s children/ fly kites in the park/ usually. ………………………………………………………………………………………………………………… ………………………………………………………………………………… VII. Fill in the blanks: Storekeeper: Can …………………… …………………… ……………………? Vui: Yes, …………………… …………………… …………………… cooking oil, please. Storekeeper: