Faraday’s Law
Core Sentence / 核心句
Faraday’s law states that changing magnetic flux produces EMF, with a direction that opposes the flux change.
中文理解：磁通量变化率决定 induced EMF；负号表示感应效应反抗造成它的磁通变化。
Law / 定律
single turn：
turns：
average magnitude：
Lenz’s Law / 楞次定律
induced magnetic field opposes the change in flux：
- increasing flux：oppose increase；
- decreasing flux：support original direction to oppose decrease。
Flux Changes / 磁通变化渠道
change 、、 or field-region overlap。
Generator / 发电机
rotating -turn coil：
Watch Out / 易错点
- negative sign cannot be ignored in direction questions。
- multi-turn coil needs 。
- oppose flux change, not always external field。
- no motion is required if changes。
- flux angle uses area normal。