Một ống dây dài l = 60 cm, diện tích tiết điện của ốnglà S = 50 cm², có N = 1800 vòng dây. Năng lượng của từ trường tích lũy bên trong ống dây khi có dòng điện cường độ I = 4 A qua ống dây là

Một ống dây dài l = 60 cm, diện tích tiết điện của ốnglà S = 50 cm², có N = 1800 vòng dây. Năng lượng của từ trường tích lũy bên trong ống dây khi có dòng điện cường độ I = 4 A qua ống dây là

* Cho khung dây hình vuông MNPQ cạnh a chuyển động đều với vận tốc  vào vùng từ trường đều có bề dày b như hình vẽ (b > a).

Chọn t = 0 lúc cạnh NP bắt đầu vào từ trường, đồ thị nào sau đây biểu diễn dòng điện đi qua khung theo thời gian?

(Cho I_C theo chiều MNPQ là dương).

Một vòng dây có độ tự cảm L = 4.10^-2 H, điện trở không đáng kể (xem như R = 0), diện tích S = 64 cm², được đặt trong từ trường đều có cảm ứng từ tăng đều từ 0 đến B = 0,6.10^-3 T, đường cảm ứng từ vuông góc với mặt phẳng vòng dây. Cường độ I của dòng điện cảm ứng xuất hiện trong vòng dây trong thời gian cảm ứng từ thay đổi là

Một ống dây dài l = 60 cm, có N = 1600 vòng dây, diện tích tiết diện S = 40 cm². Xem như từ trường trong ống dây đều, độ tự cảm của ống dây là

Hiệu điện thế sẽ xuất hiện ở hai đầu dây dẫn cho trên hình vẽ khi dây dẫn chuyển động theo hướng

Một khung dây phẳng, diện tích 20 (cm²), gồm 10 vòng được đặt trong từ trường đều. Vectơ cảm ứng từ hợp thành với mặt phẳng khung dây một góc  và có độ lớn bằng 2.10⁻⁴ (T). Người ta làm cho từ trường giảm đều đến không trong khoảng thời gian 0,01 (s). Suất điện động cảm ứng xuất hiện trong khung dây trong thời gian từ trường biến đổi là

Một ống dây dài 20 (cm), tiết diện ngang 5 (cm²) có 1000 vòng dây. Hệ số tự cảm của ống dây là 

* Cho mạch điện như hình vẽ. Cuộn dây có hệ số tự cảm L, tụ có điện dung C.

Sau đó mở khóa k, diện tích cực đại trên tụ C là 

Một khung dây dẫn hình vuông cạnh

a = 40 cm, điện trở R = 1,6 Ω, được đặt trong một từ   

trường đều có vectơ cảm ứng từ  vuông góc với mặt

phẳng khung dây và hướng ra sau hình vẽ. Trên các

cạnh AB và CD của khung có mắc hai nguồn điện ₁ =

10 V, r₁ = 0,2 Ω, ₂ = 9 V, r₂ = 0,2 Ω. Độ lớn của B

tăng theo quy luật = 20 T/s.

Độ lớn của suất điện động cảm ứng trong mạch là

Cho hai dẫn thẳng song song điện trở không đáng kể, đặt nằm ngang trong một vùng có từ trường đều có cảm ứng từ  vuông góc với mặt phẳng của hai dây, có chiều như hình vẽ, và độ lớn B = 0,6 T. Một đầu của hai dây nối với một nguồn điện _o = 6 V, điện trở trong r₀ = 1,5 Ω, đầu kia nối với một điện trở R = 3 Ω qua một khóa K điện trở không đáng kể. Một thanh AB chiều dài l = 30 cm, điện trở r = 0,5 Ω đặt vuông góc với hai dây dẫn và trượt không ma sát với vận tốc V = 25 m/s về phía đầu có điện trở R.

Khóa K vẫn đóng. Hiệu điện thế U_BA là

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 In Germany, it's important to be serious in a work situation. They don't mix work and play so you shouldn't make jokes (31) _______ you do in the UK and USA when you first meet people. They work in a very organized way and prefer to do one thing at a time. They don't like interruptions or (32)_______ changes of schedule. Punctuality is very important so you should arrive on time for appointments. At meeting, it's important to follow the agenda and not interrupt (33) _______ speaker. If you give a presentation, you should focus (34) _______ facts and technical information and the quality of your company's products. You should also prepare well, as they may ask a lot of questions. Colleagues normally use the family names, and title - for example "Doctor" or "Professor", so you shouldn't use first names (35) _______ a person asks you to.

Question 33:     

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 In Germany, it's important to be serious in a work situation. They don't mix work and play so you shouldn't make jokes (31) _______ you do in the UK and USA when you first meet people. They work in a very organized way and prefer to do one thing at a time. They don't like interruptions or (32)_______ changes of schedule. Punctuality is very important so you should arrive on time for appointments. At meeting, it's important to follow the agenda and not interrupt (33) _______ speaker. If you give a presentation, you should focus (34) _______ facts and technical information and the quality of your company's products. You should also prepare well, as they may ask a lot of questions. Colleagues normally use the family names, and title - for example "Doctor" or "Professor", so you shouldn't use first names (35) _______ a person asks you to.

Question 34:         

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 In Germany, it's important to be serious in a work situation. They don't mix work and play so you shouldn't make jokes (31) _______ you do in the UK and USA when you first meet people. They work in a very organized way and prefer to do one thing at a time. They don't like interruptions or (32)_______ changes of schedule. Punctuality is very important so you should arrive on time for appointments. At meeting, it's important to follow the agenda and not interrupt (33) _______ speaker. If you give a presentation, you should focus (34) _______ facts and technical information and the quality of your company's products. You should also prepare well, as they may ask a lot of questions. Colleagues normally use the family names, and title - for example "Doctor" or "Professor", so you shouldn't use first names (35) _______ a person asks you to.

Question 35:         

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 The warming of the Pacific Ocean has created weather pattern (31)_______ strongly affect the world. When the water is warm, the amount of rainfall in Indonesia and the surrounding regions decreases. Australia could (32)_______ experience a drought in many parts. On the other hand, Chile (which borders the Pacific Ocean) is preparing for severe rainstorms. In Pakistan and northwestern India, the weather pattern makes the rainy season weaker and makes the area much drier. This happening is called El Nino and is used (33)_______ weather forecasters to make long-range weather predictions. They also know that El Nino will bring unusually rain to the southwestern part of the United States and make the central part of the country drier at the same time. According to research, weather forecasters (34)_______ know about the coming weather with certainty. Now everything has become completely different. El Nino itself used to be predictable. It would occur every two to seven years. But now this weather pattern is becoming more frequent. We cannot say when and how often tornadoes or cyclones occur. Scientists are unsure of the reason for this (35)_______ on the global scale either.

Question 34:     

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 The warming of the Pacific Ocean has created weather pattern (31)_______ strongly affect the world. When the water is warm, the amount of rainfall in Indonesia and the surrounding regions decreases. Australia could (32)_______ experience a drought in many parts. On the other hand, Chile (which borders the Pacific Ocean) is preparing for severe rainstorms. In Pakistan and northwestern India, the weather pattern makes the rainy season weaker and makes the area much drier. This happening is called El Nino and is used (33)_______ weather forecasters to make long-range weather predictions. They also know that El Nino will bring unusually rain to the southwestern part of the United States and make the central part of the country drier at the same time. According to research, weather forecasters (34)_______ know about the coming weather with certainty. Now everything has become completely different. El Nino itself used to be predictable. It would occur every two to seven years. But now this weather pattern is becoming more frequent. We cannot say when and how often tornadoes or cyclones occur. Scientists are unsure of the reason for this (35)_______ on the global scale either.

Question 33:     

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

 The warming of the Pacific Ocean has created weather pattern (31)_______ strongly affect the world. When the water is warm, the amount of rainfall in Indonesia and the surrounding regions decreases. Australia could (32)_______ experience a drought in many parts. On the other hand, Chile (which borders the Pacific Ocean) is preparing for severe rainstorms. In Pakistan and northwestern India, the weather pattern makes the rainy season weaker and makes the area much drier. This happening is called El Nino and is used (33)_______ weather forecasters to make long-range weather predictions. They also know that El Nino will bring unusually rain to the southwestern part of the United States and make the central part of the country drier at the same time. According to research, weather forecasters (34)_______ know about the coming weather with certainty. Now everything has become completely different. El Nino itself used to be predictable. It would occur every two to seven years. But now this weather pattern is becoming more frequent. We cannot say when and how often tornadoes or cyclones occur. Scientists are unsure of the reason for this (35)_______ on the global scale either.

Question 35:         

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 7 to 11:

When you first apply for a job, you (7)…………not succeed in getting it. It’s always a good (8)……………to ask them to explain to you what prevent you from beating the other candidates. Don’t complain about the situation, but ask them to advise you (9)………………what you can do better next time. Perhaps the interviewer disapproved of or disagree with something you said. Perhaps they just glanced at your application and saw something that made it easy to choose between you and another candidate. Don’t regard it as a failure, but recognize it as a chance to learn more. (10) ………………you don’t worry too much about it and continue to believe in yourself, you’ll eventually find the chance you’ve been waiting for. Then, your family and friends will be able to (11)…………you on your success.

Question 10:

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 7 to 11:

When you first apply for a job, you (7)…………not succeed in getting it. It’s always a good (8)……………to ask them to explain to you what prevent you from beating the other candidates. Don’t complain about the situation, but ask them to advise you (9)………………what you can do better next time. Perhaps the interviewer disapproved of or disagree with something you said. Perhaps they just glanced at your application and saw something that made it easy to choose between you and another candidate. Don’t regard it as a failure, but recognize it as a chance to learn more. (10) ………………you don’t worry too much about it and continue to believe in yourself, you’ll eventually find the chance you’ve been waiting for. Then, your family and friends will be able to (11)…………you on your success.

Question 9:

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 7 to 11:

When you first apply for a job, you (7)…………not succeed in getting it. It’s always a good (8)……………to ask them to explain to you what prevent you from beating the other candidates. Don’t complain about the situation, but ask them to advise you (9)………………what you can do better next time. Perhaps the interviewer disapproved of or disagree with something you said. Perhaps they just glanced at your application and saw something that made it easy to choose between you and another candidate. Don’t regard it as a failure, but recognize it as a chance to learn more. (10) ………………you don’t worry too much about it and continue to believe in yourself, you’ll eventually find the chance you’ve been waiting for. Then, your family and friends will be able to (11)…………you on your success.

Question 8:

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 7 to 11:

When you first apply for a job, you (7)…………not succeed in getting it. It’s always a good (8)……………to ask them to explain to you what prevent you from beating the other candidates. Don’t complain about the situation, but ask them to advise you (9)………………what you can do better next time. Perhaps the interviewer disapproved of or disagree with something you said. Perhaps they just glanced at your application and saw something that made it easy to choose between you and another candidate. Don’t regard it as a failure, but recognize it as a chance to learn more. (10) ………………you don’t worry too much about it and continue to believe in yourself, you’ll eventually find the chance you’ve been waiting for. Then, your family and friends will be able to (11)…………you on your success.

Question 7: