[Vật Lý 11] Ôn tập học kì 2 - THPT Nguyễn Huệ - Thầy VNA

Hello, my name is Duong Nguyen. Hello Cam. Why are there so many 2 and 4s? Today, I just finished eating and woke up. I woke up at 5am. Then, I woke up at 2pm. Until now, I have just been eating for about half an hour. In general, I woke up from 5am to 6.30am. Then, I woke up from 2pm to now. Wow, today I'm really tired. Then, I woke up at 5am again. This week is really hard. Who is 2k4? Who is 2k5? Because tonight, the main character is 2k5. There are 100 people in the group who voted for 2k5. I don't know who is 2k5 or 2k3. 2k5 or 2k3? 2k5 or 2k4? Is there 2k6? There are 100 people in the group who voted for 2k5. I don't share this live stream to 2k4. I don't share it to 2k4. I still share it to 2k4. I can say, Thien Vy. See? Ok. Is it too late to learn 2k5? Now, the show has just begun. I haven't officially announced 2k5 yet. I just started 2k5 a little earlier. I haven't officially... I haven't officially chosen a beautiful day to announce 2k5 yet. Ok. Today, I will give you a mid-term exam. From Nguyen Hue High School, Hanoi. Maybe it's from Nguyen Hue High School, Hanoi. Today, all of our subjects are in grade 11. It comes to math. It falls into... How many schools does it fall into? It falls into 4, 5, 6, 7. It falls into 4 schools. It falls into 4 schools in grade 11. Ok? By the way, I would like to inform you that 2k5 students who are watching this live stream, Ngoc Anh is teaching the 12th grade program soon. I haven't officially announced it yet. But I have posted the lessons for 2k5 students in the group already. Some of you have learned quite a lot of 2k5's 12th grade lessons already. You encouraged me so much that I posted it first. But I haven't officially announced 2k5 yet. But it's in the early 2k5 stage. If you are 2k5 and want to join Ngoc Anh's team, you can inbox about the fanpage to get advice. If you register early, you will be given 3 books. You will learn for a whole year. You don't have to spend money to print documents anymore. You will learn for a whole year with 2k5. If you are 2k4 and want to learn 2k5, you can introduce Ngoc Anh. Ngoc Anh has taught the 12th grade program for 2k5 students already. Let's start learning. There are 40 questions today. Each question is 1 hour. Only 1 hour. We will finish this test. And of course, this test will be quite theoretical. You will mainly be weak in theory. Let's start. After finishing today's lesson, I will become a pro-whip in theory. Let's start. The first question. A magnetic field is a material that exists around a magnet, around an electric current, and around a moving electron. A static electron does not have a magnetic field. Because around a static electron, there is a magnetic field. So our first question. The answer is D. Everything is correct. A magnetic field exists around a magnet, around an electric current, and around a moving electron. OK? The answer is D. Next. The second question. The answer is correct. A magnetic field does not interact with a static electron. It interacts with a moving electron. Got it? Specifically, a moving electron in a magnetic field will be affected by a force. It is the Lorentz force. Got it? The third question. The direction of the Lorentz force around the electric current is determined by the rule of right-hand holding. Got it? For example, the electric current has a direction like this. Our Lorentz force is around it. It lies in a square plane with the electric current. And according to the rule of right-hand holding. OK? The answer is A. The answer is correct. The fourth question. Which statement is wrong? The answer is wrong. It is the same direction as the Lorentz force. Pay attention. For example, the Lorentz force is applied to a wire. This is our wire. The wire carries the electric current. Our Lorentz force is outwards. Got it? So how do you determine the Lorentz force? By shaking your left hand. Got it? In general, when it comes to force, you have to use your left hand. Put your left hand in the direction of your thumb. This is the direction of the electric current. The Lorentz force is applied to the palm of your hand. Right? And the direction of the left hand is the direction of the Lorentz force. Right? This is F. So F and B must be perpendicular to each other. Right? They cannot be in the same direction. So the Lorentz force and the Lorentz force are perpendicular. OK? The same direction is wrong. 4 is B is wrong. The fifth question. The Lorentz force applied to the wire does not depend directly on which one? The Lorentz force applied to the wire is F by BIL. Like Sin Alpha. Right? It does not depend on the Lorentz force of the wire. So the fifth question is D. Right? It depends on both the magnetic field and the electric current. And in the long term. It does not depend on the Lorentz force. 5 is D. Next, the sixth question. Which force is not the magnetic field? The magnetic field is the interaction between the male and the male. The electric current and the electric current. Or the male and the electric current. Got it? There. It interacts with the guys around it. It has magnetic field. Got it? So the magnetic field is not the force of the earth. The force of the earth is the Lorentz force. Got it? The sixth question. The answer A is correct. The seventh question is difficult. Which phrase is incorrect? 7. There is a guy named Trịnh Hồ Quỳnh Như. Right? The comment is C. Is it correct? An electric current is placed in the square of the magnetic field. Okay. Square of the magnetic field. It is placed in the square of the magnetic field. Here. Got it? Our B. Let's take an example. In this way. Right? B goes down. So what is the direction of our magnetic field now? Our magnetic field is now inward. Got it? You apply the rule of the left hand. Right? The force of the magnetic field is placed in the palm of the hand. The magnetic field from the neck to the thumb is the electric current. And the thumb presses the magnetic field. Got it? The magnetic field is placed inward. The magnetic field will not change. That is, the magnetic field must still be placed inward. Got it? The force of the magnetic field must still be placed inward. Then you have to change the direction of both I and B. There. Because if only one of the two changes the direction, then F will change the direction. Got it? You apply the rule of the left hand. Right? Apply the rule of the left hand. Put your hand like this. Is it correct? Put your left hand. Oh, it's a bit difficult to choose the direction. The direction of I is here. B is placed in the palm of the hand. So the force of the magnetic field is still placed inward. Got it? The force of the magnetic field is still placed inward. Okay? There. That is, in order for the force of the magnetic field not to change, you have to change the direction of both I and B. Got it? There. That is, in order for the force of the magnetic field not to change, you have to change the direction of both I and B. Got it? Is it difficult? This is class 11, guys. And this part can be a university exam. This is class 12. Next, question 8. A 10-meter-long wire with a 10-ampere current placed in the magnetic field is 0.1 Tesla. The force is 0.5 Newton. The angle between the magnetic field and the current. Here. You just applied the formula I just gave you. F is equal to BIL plus sin alpha. Got it? From here, you calculate F. F is equal to BIL plus sin alpha. Question 26 Question 27