第二类电学黑箱问题是各地中考的常见题型.与第一类电学黑箱问题的区别在于,这类题不是只给出一个孤立的黑箱,而是给出一个完整的电路,黑箱内的电路是整个电路的一部分,题中通过对外接电路部分的描述显示黑箱内电路的电学性质,要求据此确定黑箱内的电路结构.这类题分为外接电路 The second kind of electrical black box problem is a common question type in local examinations. The difference from the first kind of electrical black box problem is that such questions are not only given an isolated black box, but give a complete circuit, the circuit in the black box It is a part of the entire circuit. The description of the external circuit part shows the electrical properties of the circuit in the black box. It is required to determine the circuit structure in the black box. Such questions are divided into external circuits.