Sections
Key Equations

# Key Equations

 Coulomb’s law $F=kq1q2r2F=kq1q2r2$
 electric field $E→=F→qtestE→=F→qtest$ magnitude of electric field of point charge $E=k|Q|r2E=k|Q|r2$
 change in electric potential energy for a charge that moves in a constant electric field $ΔUE=−qE(xf−xi)ΔUE=−qE(xf−xi)$ electric potential energy of a charge a distance r from a point charge or sphere of uniform charge $UE=kQqrUE=kQqr$ definition of electric potential $V=UEqV=UEq$ change in electric potential for a charge that moves in a constant electric field $ΔV=−E(xf−xi)ΔV=−E(xf−xi)$ electric potential of a charge a distance r from a point charge or sphere of uniform charge $V=kQrV=kQr$
 capacitance $C=QVC=QV$ energy stored in a capacitor $UE=12CV2UE=12CV2$ capacitance of a parallel-plate capacitor $C=κε0AdC=κε0Ad$