Một ống dây hình trụ dài gồm N = 800 vòng dây, diện tích mỗi vòng S = 50 cm², được đặt trong từ trường đều có vectơ cảm ứng từ  song song với trục ống dây và cường độ tăng dần đều theo quy luật  = 2.10^-2 T/s. Người ta nối hai đầu ống dây với một tụ điện C = 6.10^-5 F. Năng lượng tích lũy trong tụ điện là

Một thanh dẫn điện dài 20 (cm) tịnh tiến trong từ trường đều, cảm ứng từ B = 5.10⁻⁴ (T). Vectơ vận tốc của thanh vuông góc với vectơ cảm ứng từ và có độ lớn bằng 2 (m/s). Suất điện động cảm ứng trong thanh bằng

Khung dây MNPQ nằm trong từ trường đều  như hình vẽ. Khi khung dây quay quanh cạnh MN thì suất điện động sẽ đổi chiều trong một vòng quay số lần là

Một ống dây hình trụ dài gồm N = 800 vòng dây, diện tích mỗi vòng S = 50 cm², được đặt trong từ trường đều có vectơ cảm ứng từ  song song với trục ống dây và cường độ tăng dần đều theo quy luật  = 2.10^-2 T/s. Người ta nối hai đầu ống dây với một tụ điện C = 6.10^-5 F. Năng lượng tích lũy trong tụ điện là

Phát biểu nào sau đây không đúng?

Một ống dây gồm N = 800 vòng dây, có chiều dài l = 40 cm, diện tích mỗi vòng S = 20 cm², có dòng điện I = 6 A đi qua:

Từ thông Φ₁ đi qua mỗi vòng dây là

Cho hai ống dây L₁, L₂ đặt đồng trục, L₂ nằm bên trong L₁ như trên (hình a). Hai đầu ống dây L₂ nối với điện trở R. Dòng điện I₁ qua ống dây L₁ biến đổi theo thời gian được biểu diễn trên (hình b). Khi đó qua ống dây L₂ có dòng điện I₂.

Trong số bốn đồ thị được cho bên dưới, đồ thị nào có thể coi là biểu diễn đúng sự phụ thuộc của dòng I₂ vào thời gian?

* Cho khung dây ABCD có hai điện trở R₁, R₂ và thanh MN chuyển động với vận tốc v dọc theo hai thanh AB và CD. Hệ thống đặt trong từ trường đều  như hình vẽ. Bỏ qua điện trở các thanh.

Cho B = 0,1 (T); MN = 20 (cm). R₁ = 0,1 (Ω); R₂ = 0,4 (Ω); v = 4 (m/s) thì dòng điện qua MN là 

Một ống dây hình trụ dài l = 40 cm gồm N = 1200 vòng dây, điện tích mỗi vòng S = 20 cm². Suất điện động cảm ứng xuất hiện trong ống dây khi dòng điện qua cuộn dây thay đổi đều từ 2 A đến 10 A trong 4 s là

Cho hai thanh kim loại song song,

thẳng đứng, điện trở không đáng kể, một đầu nối

với điện trở R = 1,5 Ω. Một thanh dây dẫn AB, có

chiều dài l = 15 cm, khối lượng m = 2,5 g, điện trở

R = 1,5 Ω trượt không ma sát xuống dưới với vận

tốc v và luôn luôn vuông gốc với hai thanh kim loại.    

Toàn bộ hệ thống được đặt trong từ trường  có

 phương vuông góc với mặt phẳng hai thanh kim

loại, chiều như hình vẽ, có cảm ứng từ B = 0,5 T.

Cho g = 9,8 m/s² và dòng điện qua AB có chiều từ B sang A, I = C

Cường độ dòng điện cảm ứng qua dây dẫn AB khi vận tốc V của dây đạt giá trị

v₀ = 8,7 m/s   là

Sự biến đổi của dòng điện trong một mạch điện theo thời gian được cho trên hình vẽ. Gọi suất điện động tự cảm trong khoảng thời gian từ 0 (s) đến 1 (s) là , từ 1 (s) đến 3 (s) là . Hệ thức nào sau đây là đúng?

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 31 to 35:

THE FIRST WOMAN SCIENTIST Hypatia was born in Alexandria, in Egypt, in 370 A.D. For many centuries, she was the only woman scientist to have a place in the history books. Hypatia’s father was director of Alexandria University, and he (31) ________ sure his daughter had the best education available. This was unusual, as most women then had few (32) ________ to study. After studying in Athens and Rome, Hypatia returned to Alexandria where she began teaching mathematics. She soon became famous (33) ________ her knowledge of new ideas. We have no copies of her book, but we know that she wrote several important mathematical works. Hypatia was also interested in technology and invented several scientific tools to help with her work. At the (34) ________, many rulers were afraid of science, and anyone connected with it was in danger. One day in March 415, Hypatia (35) ________ attacked in the street and killed.  

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:

All relationships go through difficult times. In the past, when married couples had problems they usually didn’t (31) _________. They had to either (32) _________ with each other or continue to live together in an unhappy relationship. Getting divorced wasn’t an option for most people due to economic and social reasons. Some people believe that this wasn’t such a bad thing. They say that relationships require hard work and (33) _________. “If a relationship is going to last a lifetime, you have to keep working at it,” says Doreen, who is celebrating her fiftieth wedding anniversary this year. “It isn’t all roses and romance. No one perfect all of the time. These days young people give up when there’s the (34) _________ argument.” Experts agree that communication is key. The most important thing is to keep talking. How many times have you heard yourself say to somebody, “If only you’d listen!” or “I wish you wouldn’t do that!” The truth is, the (35) ______ couples talk, the better their relationship can be.  

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:

All relationships go through difficult times. In the past, when married couples had problems they usually didn’t (31) _________. They had to either (32) _________ with each other or continue to live together in an unhappy relationship. Getting divorced wasn’t an option for most people due to economic and social reasons. Some people believe that this wasn’t such a bad thing. They say that relationships require hard work and (33) _________. “If a relationship is going to last a lifetime, you have to keep working at it,” says Doreen, who is celebrating her fiftieth wedding anniversary this year. “It isn’t all roses and romance. No one perfect all of the time. These days young people give up when there’s the (34) _________ argument.” Experts agree that communication is key. The most important thing is to keep talking. How many times have you heard yourself say to somebody, “If only you’d listen!” or “I wish you wouldn’t do that!” The truth is, the (35) ______ couples talk, the better their relationship can be.  

Question 34:

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 31 to 35:

One of the hottest topics on the international development agenda is how to harness the power of International Monetary Fund for the benefit of developing countries. What is sometimes called “the death of distance”, brought about by the Internet, allow professional services such as (31) ________ education and training to be provided easily and quickly to (32) ________ areas. Some of the gains can be seen in countries as diverse as India and Morocco, where innovations range from (33) ________ government announcements to local craftsmen selling their wares to a (34)________ market. But already a huge and expanding digital divide is opening up between developed and developing nations. The major tasks facing world leaders at present is to supply everybody on the planet with clean water, basic education and the drugs needed to fight preventable diseases. Installing a modem in every classroom and linking us to (35) ________ must be a lesser criteria at least.  

Question 34:        

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 31 to 35:

One of the hottest topics on the international development agenda is how to harness the power of International Monetary Fund for the benefit of developing countries. What is sometimes called “the death of distance”, brought about by the Internet, allow professional services such as (31) ________ education and training to be provided easily and quickly to (32) ________ areas. Some of the gains can be seen in countries as diverse as India and Morocco, where innovations range from (33) ________ government announcements to local craftsmen selling their wares to a (34)_______ market. But already a huge and expanding digital divide is opening up between developed and developing nations. The major tasks facing world leaders at present is to supply everybody on the planet with clean water, basic education and the drugs needed to fight preventable diseases. Installing a modem in every classroom and linking us to (35) ________ must be a lesser criteria at least.  

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:

Many people today would like the traditional two-parent family back, that is to say, they want a man and a woman to (31)______ for life; they also think the man should support the family and the woman should stay home with the children. However, few families now (32)______ into this category. In fact, if more women decide to have children on their own, the single-parent household may become more typical than the traditional family in many countries. Also, unmarried couples may decide to have more children – or they might take in foster children or (33)______. And because people are staying single and living longer (often as widows), there may be more one-person households. (34)______ the other hand, some people believe similar events happen again and again in history: if this is true, people may go back to the traditional (35)_____ or nuclear family of the past. Others think the only certainty in history is change: in other words, the structure of the future family could begin to change faster and faster and in more and more ways.  

Question 34:

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:

TRANSPORT IN THE CITY

Transport plays an important role in our daily lives and in the quality of life in our city. Moreover, the individual decisions we make when we choose how to (38)_______our destination can have an impact (39) _____other people – longer traffic queues, worsening air quality, greater number of accidents and health problems. Providing more transport options will create a transport system that is safe, clean and fair. Increasing use of the car has led to greater (40) ____ of the impact it has and the real cost to us – for our health, for the economy and for the environment. We want our city to become a successful, cosmopolitan city by the sea, (41) _______people can enjoy a high quality of life in a pleasant environment. To (42)_______this we need to make sure everyone has access to the services and facilities they need, through a choice of as many different means of transport as possible.

Question 38:  

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:

TRANSPORT IN THE CITY

Transport plays an important role in our daily lives and in the quality of life in our city. Moreover, the individual decisions we make when we choose how to (38)_______our destination can have an impact (39) _____other people – longer traffic queues, worsening air quality, greater number of accidents and health problems. Providing more transport options will create a transport system that is safe, clean and fair. Increasing use of the car has led to greater (40) ____ of the impact it has and the real cost to us – for our health, for the economy and for the environment. We want our city to become a successful, cosmopolitan city by the sea, (41) _______people can enjoy a high quality of life in a pleasant environment. To (42)_______this we need to make sure everyone has access to the services and facilities they need, through a choice of as many different means of transport as possible.

Question 39:  

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:

TRANSPORT IN THE CITY

Transport plays an important role in our daily lives and in the quality of life in our city. Moreover, the individual decisions we make when we choose how to (38)_______our destination can have an impact (39) _____other people – longer traffic queues, worsening air quality, greater number of accidents and health problems. Providing more transport options will create a transport system that is safe, clean and fair. Increasing use of the car has led to greater (40) ____ of the impact it has and the real cost to us – for our health, for the economy and for the environment. We want our city to become a successful, cosmopolitan city by the sea, (41) _______people can enjoy a high quality of life in a pleasant environment. To (42)_______this we need to make sure everyone has access to the services and facilities they need, through a choice of as many different means of transport as possible.  

Question 40:

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:

TRANSPORT IN THE CITY

Transport plays an important role in our daily lives and in the quality of life in our city. Moreover, the individual decisions we make when we choose how to (38)_______our destination can have an impact (39) _____other people – longer traffic queues, worsening air quality, greater number of accidents and health problems. Providing more transport options will create a transport system that is safe, clean and fair. Increasing use of the car has led to greater (40) ____ of the impact it has and the real cost to us – for our health, for the economy and for the environment. We want our city to become a successful, cosmopolitan city by the sea, (41) _______people can enjoy a high quality of life in a pleasant environment. To (42)_______this we need to make sure everyone has access to the services and facilities they need, through a choice of as many different means of transport as possible.

Question 41: