1) The document discusses key concepts related to electric forces, fields, and circuits including that electric fields point in the direction of force on a positive test charge and capacitance depends on surface area, plate separation, and dielectric material.
2) Important vocabulary is defined like conductors, electric fields, capacitors, and dielectrics.
3) Formulas are presented for calculating values like charge, Coulomb's law, electric field, potential, capacitance, current, and resistance.
3. Main Concepts of Electric Forces and Fields Electric forces and electric fields are vectors, electric potentials are scalars Electric fields point in the direction of the force on a positive test charge Capacitance is the ratio of charge to the potential for a given conductor The capacitance for a parallel-plate capacitor depends on the surface area of each plate, the plate seperation and the permittivity or dielectric constant The capacitance of a system of parallel plates depends only on the physical characteristics of the capacitor (i.e. Surface area, plate seperation, dielectric material)
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5. Important Vocabulary Electrostatics – is the study of interaction between electric charges which are not moving Conductors – are materials in which the electrons are free to move. Some examples such as silver, copper, gold, and mercury as metals Electric Fields – exist in the space surrounding a charged particle or object Capacitor- stores electric charge and consists of two conductors seperated by an insulator known as a dielectric Dielectric – is an electrical insulator that can be polarized by an applied electrical field Electric Current – is the rate of flow of electric charge. Used in Amperes (I) where 1 Ampere is 1 coulumb/second Electrical Resistance refers to the opposition offered by a substance to the flow of electrical current. Unit of resistance is Ohm
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7. Important Formulas Electric Charge: q = n e ; where e = 1.6 X 10-19 C; (q) is the total charge on an object, (e) is the fundmental unit of charge, (n) is the number of total charges Coulomb’s Law: F = k Q1 Q2/r2 ; where k = 9 X 109 N m2 /C2 ; (F) is the two charges exerted a force (Q) is the magnitude of the charge while (r) is the square of the distance between centers
8. Important Formulas # 2 Electric Field: E = F/q or F = q E ; (E) is the magnitude of electric field, (F) force exerted om test charges, (q) is the magnittude of the charge of test particle Electric Field to a Point Charge: E = k Q /r2 ; (E) is the magnitude of electric field, (F) force exerted om test charges, and (r) is the distance from the charge
9. Important Formulas # 3 Electric Potential: V = PEa / q ; (PEa) is the potential energy, (q) per unit charge (V) is the electric potential at point Capacitance: C = Q/V ; (C) is the ratio of the charge stored, (Q) is the potential difference, (V) is between the conducting surfaces Electric Current: I = Q/t ; (I) is the electric current in Amperes Electrical Resistance: R = p L/A ; (R) is the resistance of metal wire, (L) length, (A) cross-sectional area, (p) is the resistivity Ohm’s Law: I = V/R or V = IR ; (I) stands for electric current and (V) stands for voltage of current and (R) stands for the resisitivity
10. Main Concepts: Electric Circuits An electrical network with a closed path Measured in terms of the number of charge carriers, or Particles containing a unit electric charge The current flows through a resistance
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12. Important Vocabulary Electric circuit: a continuous closed path in with electric charges can flow Electric current: flow of charged particles; conventionally, flow of positive charges Electric power: the rate at which work is done or energy is dissipated through a resistor Electrical resistance: the ratio of the voltage across a device to the current running through it Capacitor: two oppositely charged conductors used to store charge and energy in an electric field between them Resistor: device designed to have a specific resistance Resistivity: the constant which relates the resistance of a resistor to its length and cross sectional area
13. Vocabulary Continued Ammeter: device used to measure electrical current Ampere: unit of electrical current equal to one coulomb per second Battery: device that converts chemical energy into electrical energy, creating a potential difference Voltage: the potential difference between the positive and negative terminals of a battery
