The electric potential difference Equal to the work done per unit charge and measured in Joules/ coulomb or VOLTS. W = Eq in the direction of E qEΔV ΔU= Capacitor A device that stores charge and energy. The capacitance of a capacitor is the amount of charge stored per unit volt, farads (F). C = Q/V = €oA/d Electric field lines Indicate the direction of electric force on positive charges. They come out of a positive source charges and into negative source charges. They never cross and their relative spacing indicates the strength of the field. Electric field strength (E) is found by: E = F/q Units: N/C Equipotential lines Indicate regions of constant electric potential. These lines (surfaces), intersect the electric field lines at right angles. The highest values are near positive source charges and the lowest is near negative source charges. The electron volt (eV) is a unit of electrical energy. 1eV = 1.6 x 10-19j Review Section 6: Electric Circuits Current and Electricity (I) units: amps. The direction is from + to -. Measured with an Ammeter (current flows through the ammeter). I=ΔQ/Δt Electromotive force (emf) The battery that supplies potential difference needed to – maintain continuous flow of charge. Not a force, measured in volts (v). Know your Circuit symbols for wire, switch, battery, Ammeter, voltmeter, capacitor, bulb, resistor. Electric Resistance (R): R = V/I *at constant temperatures Units: Ohms(Ω) Rwire = = resistivity of material ρL/A ρ OHMS LAW:
The electric potential difference Equal to the work done per unit charge and measured in Joules/ coulomb or VOLTS. W = Eq in the direction of E ΔU= qEΔV Capacitor A device that stores charge and energy. The capacitance of a capacitor is the amount of charge stored per unit volt, farads (F). C = Q/V = €oA/d Electric field lines Indicate the direction of electric force on positive charges. They come out of a positive source charges and into negative source charges. They never cross and their relative spacing indicates the strength of the field. Electric field strength (E) is found by: E = F/q Units: N/C Equipotential lines Indicate regions of constant electric potential. These lines (surfaces), intersect the electric field lines at right angles. The highest values are near positive source charges and the lowest is near negative source charges. The electron volt (eV) is a unit of electrical energy. 1eV = 1.6 x 10-19j Review Section 6: Electric Circuits Current and Electricity (I) units: amps. The direction is from + to -. Measured with an Ammeter (current flows through the ammeter). I=ΔQ/Δt Electromotive force (emf) – The battery that supplies potential difference needed to maintain continuous flow of charge. Not a force, measured in volts (v). Know your Circuit symbols for wire, switch, battery, Ammeter, voltmeter, capacitor, bulb, resistor. Electric Resistance (R): R = V/I *at constant temperatures Units: Ohms(Ω) Rwire = ρL/A ρ = resistivity of material OHMS LAW:
AP_PHYSICS_II_EXAM_Study_Guide_rough_Final.docx