user-avatar
emxuan571994
2 năm trước
Trên một bóng đèn có ghi 6V. Khi đặt hai đầu bóng đèn vào HĐT U1=3V thì dòng điện qua đèn có cường độ I1, khi đặt đèn vào HĐT U2=5V thì dòng điện chạy qua đèn có cường độ là I2. a, So sánh I1 và I2? Giải thích? b, Phải mắc đèn vào HĐT bao nhiêu để đèn sáng bình thường? Vì sao? Mình cảm ơn.
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

In Britain, the climate is not very good. There are very few hot days and it rains a lot. Because of this, people spend a lot of time at home. Generally, British homes have a lot of furniture in them, carpets on the floors and heavy curtains. Many houses in Britain are old. Many of them are over one hundred years old. Often, they do not have enough insulation and the heat goes out through the windows, the doors and up the chimney. Because of the climate, people in Britain have to spend a lot of money on heating. Many houses have a special system called "central heating". This heats all the rooms and, at the same time, heats the hot water. Houses without central heating often have gas, electric or coal fires. The rooms in most British houses are quite small. New houses are much better. They have two layers of glass in the windows to stop the heat going out. 37. Why do British people spend a lot of time at home? A. Because the climate is not very good. B. Because they don't know where to go. C. Because the climate is very good. D. Because they want to stay at home. 38. The heat goes out of the houses through_____ . A. the doors and up the chimney B. the windows and up the chimney C. the windows, the doors and up the chimney D. the walls and up the chimney 39. Because of______ , people in Britain have to spend a lot of money on heating. A. cold weather B. cool weather C. hot weather D. bad weather 40. Houses without central heating often have_____ . A. only coal fires B. gas or coal fires C. electric or coal fires D. gas, electric or coal fires 41. New houses usually have______ in the windows to stop the heat going out. A. one layer of glass B. two layers of glass C. three layers of glass D. two or three layers of glass

8 Mark the letter A, B, C or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges. Question 14. Paul: “There are many stilt houses in the north region of Viet Nam.”. Tom: “__________.” A. I can’t see them B. They sound interesting C. Do you like it? D. Where are the stilt houses? 9 Choose the sentence (A, B, C or D ) that is closest in meaning to the given one . Question 24: There are many factors contributing to air pollution. A. Factors contributing to air pollution are numerous. B. Air pollution is contributing to these phenomena. C. Air pollution results in many consequences. D. Air pollution is the result of burning forests. 10 Choose the word whose underlined part is pronounced differently from the others. A. event B. percent C. netiquette D. face 11 Choose the underlined part A, B, C or D that needs correcting. Picture 16 A. A B. B C. C D. D 12 Choose the sentence (A, B, C or D ) that is closest in meaning to the given one . Question 23: He was such a smart student that he could solve all the math problems. A. All the math problems were so smart that he could solve them. B. The math problems were too difficult for him to solve. C. He was not smart enough to solve all the math problems. D. He was so intelligent that he could solve all the math problems. 13 Mark the letter A, B, C or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges. Question 13. Jane: “I like learning a new language. I’m learning Japanese at the moment.” Laura: “________” A. Why not? B. Do you like it? C. Is it very good? D. Why did you choose Japanese? 14 Choose the best answer A, B, C or D to complete the sentence. Question 7: I was glad _______ see him again after ten years. . A. to seeing B. seeing C. to see D. see 15 Choose the underlined part A, B, C or D that needs correcting. Picture 17 A. A B. B C. C D. D 16 Choose the best answer A, B, C or D to complete the sentence. Question 9: She expects _______a doctor. A. to become B. to becoming C. becoming D. become 17 Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) to each of the following questions. Question 15. Scientists have recently argued that Einstein’s contributions to Physics and Mathematics are less important than Newton’s. A. before B. shortly C. just now D. at once 18 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 blank (19). Sa Pa’s love market has become unique in the culture of the Mong and Dao ethnic groups (17) ______ a long time. Due to the distance between the villages, the market meets once a week on Sunday. On the Saturday night, guys and girls from villages come to Lao Cai (18) ______ one another. They talk, sing and (19) ______ different games according to their ethnic groups’ tradition. After the night, many couples become intimate and promise to see each other again on the following morning. Many of (20) ______ become husbands and wives in the spring. That is why the poets in Lao Cai called the market Sapa’s Love Market. The most popular Love Market in Lao Cai is organized in nowhere else but Sa Pa, where it is gaining more and more (21) ______ of not only the ethnic people but also the travelers from many places in the world. A. play B. get C. perform D. help 19 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 blank (20). Sa Pa’s love market has become unique in the culture of the Mong and Dao ethnic groups (17) ______ a long time. Due to the distance between the villages, the market meets once a week on Sunday. On the Saturday night, guys and girls from villages come to Lao Cai (18) ______ one another. They talk, sing and (19) ______ different games according to their ethnic groups’ tradition. After the night, many couples become intimate and promise to see each other again on the following morning. Many of (20) ______ become husbands and wives in the spring. That is why the poets in Lao Cai called the market Sapa’s Love Market. The most popular Love Market in Lao Cai is organized in nowhere else but Sa Pa, where it is gaining more and more (21) ______ of not only the ethnic people but also the travelers from many places in the world. A. her B. his C. them D. us 20 Choose the best answer A, B, C or D to complete the sentence. Question 12: If the area is hit by the storm, a lot of damage _______ A. will cause B. caused C. would cause D. will be caused

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team