交变电流是前面学过的电磁学知识的发展和应用,是整个电磁学内容的提高和升华,并且与生产、生活有着密切联系,在电磁学中占有重要地位．在理综考试中交流电与其他电学知识的综合是近几年高考命题的热点内容． Alternating current is the development and application of electromagnetic knowledge learned in the past. It is the improvement and sublimation of the entire electromagnetic content. It is closely related to production and life, and occupies an important position in electromagnetics. The integration of AC and other electrical knowledge in the comprehensive exam is a hot topic of the college entrance examination proposition in recent years.