Summary College Level Physics Electromagnetism Formula Sheet

​Formula Sheet​
​9​​ ​2​ ​2​
​𝑘​ ​is Coulombs Constant(​​8​. ​99​​​ · ​​1​0​ ​​𝑁​𝑚​ ​/​𝐶​ ​)​

​1. Electrostatics​

​1.​ ​Coulomb’s Law​
​𝑞​1​𝑞​2​
​𝐹​​𝑒​ = ​𝑘​ ​2​
​𝑟​


​●​ ​𝐹​​𝑒​ ​is the electric force​
​​ Q
● ​ are the charges on the two objects​
​●​ ​r is the distance between the two objects​

​2.​ E
​ lectric Field (point charge)​
​𝐹​ ​𝑄​
​𝐸​ = ​𝑞​ = ​𝑘​ ​2​
​𝑟​
​●​ ​E = electric field (N/C)​

​●​ ​Q = source charge (C)​

​●​ ​q = test charge (C)​

​●​ ​F = force on test charge (N)​

​●​ ​r = distance (m)​

​3.​ ​Electric Potential Energy (point charge)​


​𝑞​1​𝑞​2​
​𝑈​ = ​𝐾​ ​2​
​𝑟​
​U = potential energy (J)​


​4.​ ​Electric Potential (voltage)​


​𝑄​
​𝑉​ = ​𝑈𝑞​ = ​𝐾​ ​𝑟​

​●​ ​V = electric potential (V)​

​5.​ ​Relation between Electric Field & Potential​

, ∆​𝑣​
​𝐸​ =− ∆​𝑑​

​●​ ​ΔV\Delta V = change in potential (V)​

​●​ ​Δd\Delta d = distance (m)​




​2. Current & Resistance​

​6.​ ​Definition of Current​


​ ​
𝑄
​𝐼​ = ​𝑡​

​●​ ​I = current (A)​

​●​ ​Q = charge (C)​

​●​ ​T = time (s)​

​7.​ O​ hm’s Law​
​𝑉​ = ​​𝐼𝑅​
​●​ ​V = voltage (V)​

​●​ ​I = current (A)​

​●​ ​R = resistance (Ω)​

​8.​ R
​ esistance of a Material​
​𝐿​
​𝑅​ = ρ ​𝐴​
​●​ ​ρ\rho = resistivity (Ω·m)​

​●​ ​L = length (m)​

​●​ ​A= cross-sectional area (m²)​




​3. Circuits (Series & Parallel)​

​9.​ R
​ esistors in Series​
​𝑅​​𝑒𝑞​​​ = ​𝑅​​1​ + ​𝑅​​2​ +..... ​𝑅​​𝑛​