中考物理基础知识（十四）:第二十章：电与磁
Fundamental Physics Concepts for High School Entrance Examination (Part 14): Chapter 20: Electricity and Magnetism
李宏 湖北省十堰市郧阳中学
Li Hong Yunyang High School， Shiyan City， Hubei Province
{jz:field.toptypename/}第二十章：电与磁-[中考物理基础知识]
Chapter 20: Electricity and Magnetism – [Basic Physics Knowledge for High School Entrance Examination]
展开剩余86%117．磁现象：磁性、磁体、磁极、磁场、磁感线、磁化等
Magnetic phenomena: magnetism， magnetic objects， magnetic poles， magnetic fields， magnetic field lines， magnetization， etc.
118．同名磁极互相排斥，异名磁极互相吸引。
Like magnetic poles repel each other， unlike magnetic poles attract each other.
119．在磁体外部，磁感线都是从磁体的N极出发，真钱投注app官网回到S极。
Outside a magnet， magnetic field lines emerge from the N pole and return to the S pole.
120．电流的磁效应：
Magnetic effect of electric current:
（1）实验：奥斯特实验
Experiment: Oersted’s experiment
（2）内容：通电导线周围存在磁场；磁场的方向与电流方向有关。
Description: A magnetic field exists around a current-carrying conductor; the direction of the magnetic field is related to the direction of the current.
121．通电螺线管外部的磁场与条形磁体的磁场相似。
The magnetic field outside a current-carrying solenoid is similar to that of a bar magnet.
122．安培定则：
用右手握螺线管，让四指指向螺线管中的电流方向，则大拇指所指的那端就是通电螺线管的N极。
Ampere’s right-hand rule:
Grasp the solenoid with your right hand such that your fingers curl in the direction of the current in the solenoid; your extended thumb then points toward the N pole of the solenoid.
123．电磁铁的磁性强弱与电流的大小、线圈匝数以及有无铁芯有关。
The strength of an electromagnet depends on the magnitude of the current， the number of turns in the coil， and whether there is an iron core.
124．电动机的原理：通电导体在磁场中受到力的作用。
Principle of the electric motor: A current-carrying conductor experiences a force when placed in a magnetic field.
125．发电机的原理：电磁感应现象（英国 法拉第）
Principle of the generator: Electromagnetic induction (discovered by Faraday， UK).
产生感应电流的条件：闭合电路的一部分导体在磁场中做切割磁感线运动；
Conditions for generating induced current: A part of a closed circuit moves through a magnetic field， cutting across magnetic field lines.
感应电流的方向与磁场方向和导体切割磁感线的运动方向有关。
The direction of the induced current depends on the direction of the magnetic field and the direction in which the conductor cuts the magnetic field lines.
Explorer of Innovative Thinking
Author: Li Hong
Yunyang High School， Shiyan City， Hubei Province
February 9， 2026
发布于：湖北省
