Three major difficulties in physics and electrical in the middle school entrance examination!Make many junior high school students changing, it is not difficult to find a way

There are three major difficulties in the physical electrical module of the middle school entrance examination, which makes many junior high school students changing. In fact, as long as you find the right method, you can solve these three major difficulties in the short term!

The difficulty of these three major difficulties is progressing in turn.

These three major difficulties are: Ohm's Law, Electricity, and Jiao Er Law!

We need to know that the electrical module occupies a very high score in the physical test papers of the middle school entrance examination, second only to mechanics, about 30 points of about 40 points. Therefore, all junior high school students who are not well electrical science basically have themselves with themselves with themselves. The ideal high school said. Therefore, learning electrical science is not just about the usual achievements, but also about its own future. The middle school entrance examination is the first watershed in life. It is about half of the students who can get admitted to high school every year. It means that it is not a high school to pass the high school. Life that has not been in college is incomplete, and life that has not been studying in middle school that is not working hard is also incomplete. Therefore, we must learn electrical science. So, how can we thoroughly review the electrical science during the review stage of the middle school entrance examination?

Learning is the same as doing other things. To do well, you must seize the main contradictions, and the main contradiction of electrical knowledge is that the three major middle school entrance examinations to be said today are difficult.

The students in the third grade know that there are six basic physical quantities of electrical science: current, voltage, resistance, electrical and electrical, electrical, electricity, electric heating! There are many electrical formulas composed of these six basic physical quantities. The types of computing questions are endless and have a high degree of comprehensiveness. At the same time, the calculation volume is relatively large.而今天所说的这三大重难点都是中考的必考知识点，同时也会涉及到力电综合、热电综合，各种与生活用电器（比如电饭煲、电热水器、电热毯、电熨斗、 There are many comprehensive examination questions related to home appliances such as electric baked pan, hair dryers, etc.! This is exactly the same, which makes many junior high school students the most headache!

In fact, the content of the first major difficulty: Ohm's law, the content is relatively simple, because the formula is only one, plus three deformation, most junior high school students can accept and master. However, the problem is actually starting from here, and the real electrical science has also started from here, but after all, it is still a relatively basic part. Compared with the other two major difficulties, this can only be regarded as the focus.

Anyone who feels that the "Ohm Law" is difficult to consolidate the five major foundations: the first basis is "judgment of stringing and United circuits"; the second biggest foundation is "the problem of judgment object judgment of the current meter"; "The measurement of the measurement object of the voltage gauge"; the fourth problem is "the problem of the range selection of the current meter and the voltage meter"; The various questions in the Om Dingzhang chapter appear one by one, and the result will cause any major foundation for students who are not firm, and they will make mistakes in the face of this largest difficult problem! Therefore, this type of classmates should solve the targeting of their problems. These basic problems, like a fortress one by one, will break one by one one by one!

Here are a few small precautions: First, the applicable conditions of Ohm's law are pure resistance, and the formula has homogeneous and simultaneous; second, Ohm's law actually contains three proportional relationships: (simplified to say yes) current and voltage voltage Positive proportional; the voltage is proportional to the resistance; the current is inversely proportional to the resistance.

However, the second biggest difficulty: electricity (including electrical, electricity, electricity)! It has become a nightmare for many junior high school students! This knowledge module is the most difficult, the most question type, the most comprehensive, the most complicated, and the most variable -type module!

You can see the clue from the formula first. The physical formulas in this chapter are the most. The three formulas of electrical, electricity, and electrical power have a total of 14 formulas (the same as the electrical and electrical formulas). As a result, some students who have some unique foundations will not choose formulas! The result is the chaotic formula! Fortunately, these formulas actually come from the three most basic formulas. In addition to firmly grasping these formulas, the school bully will also derive the rest of the formulas. Therefore, they will be more flexible and more efficient to choose the formula when doing the questions!

In addition, from the exercises, there are too many physical problems involved in the second major difficulties! There are too many problems and comprehensive questions! It is also for this reason that this knowledge module has become the last finale of the physical examination papers of the middle school entrance examination every year!

Finally, the third major difficulty: Jiao Er Law! In fact, this knowledge point belongs to the niche type. The reason for this is because this difficult point generally appears in experimental questions and gear issues, and the second largest difficulty point of electricity appears in all types! The law of Jiao Er is the law that describes the conversion between electrical energy and internal energy. There is only one formula in the physical textbook, but there are still three derivatives! Therefore, there are still problems with formulas. It should be noted that the applicable conditions of Jiao Er's law formula are arbitrarily, but its derivative formula has restricted conditions! And pay attention to the formulas of pure resistance and non -pure resistance!

In summary, the above three major difficulties are the three major obstacles on the physical victory of the junior high school entrance examination. For the third grade students who have finished electrical and facing the middle school entrance examination, they need to break through these obstacles. As long as you are attentive, you can be proficient in electrical science for a week and successfully enter the entrance examination!

- END -