Test Charge
Core Sentence / 核心句
A test charge is an imagined small positive charge used to define electric field direction and strength.
中文理解：试探电荷用来测电场，默认正且足够小，不应明显扰动原场。
Formula / 公式或规则
When To Use / 什么时候用
判断电场方向时，想象放一个 positive test charge。
Watch Out / 易错点
不要用负试探电荷的受力方向当作电场方向。
Search and Source Mentions / 搜索与出现位置
Mentioned In / 出现位置
- AP电磁学第1次正课-电荷库仑定律与电场 · Knowledge Point 12: Electric Field Is Force per Unit Positive Test Charge
Knowledge Point 12: Electric Field Is Force per Unit Positive Test Charge
- AP电磁学第1次正课-电荷库仑定律与电场 · Knowledge Point 14: Direction of Electric Field Uses a Positive Test Charge
Knowledge Point 14: Direction of Electric Field Uses a Positive Test Charge
- AP电磁学第1次正课-电荷库仑定律与电场 · Supplement 9: Test Charge Must Be Small / 试探电荷必须足够小
Supplement 9: Test Charge Must Be Small / 试探电荷必须足够小
- AP电磁学第2次正课-连续带电体电场与电通量 · 1. The electric field is the force per unit positive test charge.
1. The electric field is the force per unit positive test charge.
- AP电磁学第1次正课-电荷库仑定律与电场 · 5. Deep Phrases / 深句对应表
| Electric field is force per unit positive test charge. | $\vec E=\vec F/q$，方向按正试探电荷定义。 |
- AP电磁学第1次正课-电荷库仑定律与电场 · 8. Confusion / Questions
9. 为什么 electric field direction 要用 positive test charge 定义？
- AP电磁学第1次正课-电荷库仑定律与电场 · Supplement 8: Superposition Applies to Force and Field / 力和场都满足叠加
Force depends on the test charge; electric field depends only on source charges.
- AP电磁学第1次正课-电荷库仑定律与电场 · Type 4: Electric Field Direction
Electric field direction is the force direction on a positive test charge.