初中物理 — 电学名词解释与公式汇总
一、欧姆定律
$I = \dfrac{U}{R}$($I$:电流/A,$U$:电压/V,$R$:电阻/Ω)
二、电功率
$P = UI = I^2R = \dfrac{U^2}{R}$($P$:电功率/W)文章源自公式库网-https://www.gongshiku.com/html/202406/chuzhongwulidianxuemingcijieshiyugongshihuizong.html
三、电功(电能)
$W = Pt = UIt = I^2Rt = \dfrac{U^2}{R}t$文章源自公式库网-https://www.gongshiku.com/html/202406/chuzhongwulidianxuemingcijieshiyugongshihuizong.html
国际单位:J(焦耳);常用单位:kW·h(千瓦时)文章源自公式库网-https://www.gongshiku.com/html/202406/chuzhongwulidianxuemingcijieshiyugongshihuizong.html
1 kW·h $= 3.6 \times 10^6\text{ J}$文章源自公式库网-https://www.gongshiku.com/html/202406/chuzhongwulidianxuemingcijieshiyugongshihuizong.html
四、焦耳定律(电流热效应)
$Q = I^2Rt$($Q$:热量/J)文章源自公式库网-https://www.gongshiku.com/html/202406/chuzhongwulidianxuemingcijieshiyugongshihuizong.html
五、串/并联电路
| 串联 | 并联 | |
|---|---|---|
| 电流 | $I = I_1 = I_2$ | $I = I_1 + I_2$ |
| 电压 | $U = U_1 + U_2$ | $U = U_1 = U_2$ |
| 电阻 | $R = R_1 + R_2$ | $\dfrac{1}{R}=\dfrac{1}{R_1}+\dfrac{1}{R_2}$ |
六、电阻定律
$R = \rho\dfrac{l}{S}$($\rho$:电阻率,$l$:长度,$S$:截面积)文章源自公式库网-https://www.gongshiku.com/html/202406/chuzhongwulidianxuemingcijieshiyugongshihuizong.html
七、电学单位
- 电压 $U$:V(伏特),1 kV = 1000 V
- 电流 $I$:A(安培),1 A = 1000 mA
- 电阻 $R$:Ω(欧姆),1 MΩ = 1000 kΩ = 10⁶ Ω
- 电功率 $P$:W(瓦特),1 kW = 1000 W