Fundamental Principles of Electricity and Circuit Theory

Electrostatics and Electric Fields

• The Coulomb: The quantity of electric charge flowing for one second through a cross-section of a conductor with a current of one Ampere.
• Coulomb's Law: The force with which two-point electric charges attract or repel each other is directly proportional to the product of these charges and inversely proportional to the square of the distance between them.
• Electric Field: This is the region of space where, at each point of origin, there is an electrostatic force caused by the presence of one or more electrical charges.
• Field Strength: At a specific point, this is the ratio of the force acting on a positive charge located at that point to the value of that charge.
• Electric Potential: At a point within an electric field, this is the electric potential energy possessed by a unit positive charge located at that point.
• Potential Difference: Between two points in an electric field, this is the quotient obtained by dividing the work done in moving a charge from one point to another by the value of that charge.

Circuit Components and Fundamentals

• Capacitor: A device consisting of two conductors close together, called plates, separated by a dielectric.
• Amperage: The amount of electron flow through a conductor in a unit of time, expressed as I = Q / t.
• Ampere (Amp): The unit where one Coulomb passes through a conductor every second.
• Ohm's Law: The intensity of current through a metallic conductor is directly proportional to the potential difference between its ends (A and B) and inversely proportional to the resistance of the conductor.
• Generator: Any device capable of transforming any type of energy into electrical energy and supplying it to the electrical charges that cross it.
• Electromotive Force (EMF) of a Generator: The relationship between the non-electric energy it transforms and the electric charge passing through it.
• Electromotive Force (EMF) of a Receiver: The relationship between the energy transformed into forms other than heat and the electrical charge passing through it.

Network Analysis and Kirchhoff's Laws

• Network: A set of conductors, resistors, EMFs, and counter-electromotive forces joined together in an arbitrary form so that currents of different or equal intensities circulate through them.
• Node: A network point where more than two conductors meet.
• Branch: The part of the network between two consecutive nodes, traversed by the same current intensity.
• Mesh: A closed conducting circuit obtained by starting from a node and returning to it without passing through the same branch twice.
• Kirchhoff's Current Law (KCL): The algebraic sum of the currents that meet at a node is equal to zero.
• Kirchhoff's Voltage Law (KVL): The sum of the potential drops over a mesh is equal to the sum of the electromotive forces and counter-electromotive forces within it.
• Principle of Superposition: If a network contains several generators, the intensity of the current in any branch is equal to the sum of the currents produced by each generator acting independently.
• Thévenin's Theorem: A network is equivalent to a single generator and an equivalent internal resistance.