4.7: End of Chapter Key Terms

Definition: Electricity

• Electric Charge: A property of subatomic particles that causes them to experience a force when placed in an electric field; measured in coulombs (C).
• Electric Current: The flow of electric charge through a conductor; measured in amperes (A).
• Voltage (Electric Potential): The difference in electric potential energy per unit charge between two points; measured in volts (V).
• Resistance: The opposition to the flow of electric current through a conductor; measured in ohms (Ω).
• Conductor: A material that allows the flow of electric charge, typically metals like copper and aluminum.
• Insulator: A material that resists the flow of electric charge, such as rubber, glass, and plastic.
• Semiconductor: A material with electrical conductivity between that of a conductor and an insulator, used in electronic devices.
• Ohm’s Law: A law stating that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R); expressed as V = IR.
• Series Circuit: An electric circuit in which components are connected end-to-end so that the current flows through each component in turn.
• Parallel Circuit: An electric circuit in which components are connected across common points or junctions, providing multiple paths for the current.
• Direct Current (DC): Electric current that flows in one direction only.
• Alternating Current (AC): Electric current that periodically reverses direction.
• Power: The rate at which electrical energy is transferred by an electric circuit; measured in watts (W).
• Capacitor: An electrical component used to store energy electrostatically in an electric field, consisting of two conductive plates separated by an insulating material.
• Inductor: An electrical component that stores energy in a magnetic field when electric current flows through it, typically a coil of wire.
• Electric Field: A field around a charged particle that exerts a force on other charged particles.
• Electromotive Force (EMF): The energy provided per charge by an energy source, such as a battery or generator; measured in volts (V).
• Coulomb’s Law: A law stating that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
• Electric Potential Energy: The energy a charged particle has due to its position in an electric field.
• Circuit Breaker: An automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.
• Fuse: A safety device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level.
• Grounding: The process of connecting an electrical circuit to the Earth to ensure safety by preventing buildup of voltages that could cause electric shocks.
• Short Circuit: A low-resistance connection between two points in an electric circuit, allowing an excessive current to flow.
• Superconductor: A material that can conduct electricity without resistance when cooled to very low temperatures.
• Electrolysis: A process that uses an electric current to drive a non-spontaneous chemical reaction.
• Kirchhoff’s Laws: Two rules regarding the conservation of current and voltage in electrical circuits: Kirchhoff’s Current Law (KCL) states that the total current entering a junction equals the total current leaving; Kirchhoff’s Voltage Law (KVL) states that the sum of the electrical potential differences around any closed circuit is zero.
• Transformers: Electrical devices that transfer electrical energy between two or more circuits through electromagnetic induction, used to increase or decrease voltage levels.
• Resistor: An electrical component that limits or regulates the flow of electrical current in an electronic circuit.
• Electric Power: The rate at which electrical energy is transferred by an electric circuit, typically expressed as the product of current and voltage (P = IV).
• Electromagnetic Induction: The production of an electromotive force across a conductor when it is exposed to a varying magnetic field.
• Faraday’s Law: A law stating that the induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic flux through the circuit.
• Lenz’s Law: A law stating that the direction of an induced current is such that it will oppose the change in magnetic flux that produced it.
• Electrical Conductivity: The measure of a material’s ability to conduct an electric current.
• Dielectric: An insulating material that can be polarized by an electric field, increasing a capacitor's ability to store charge.
• Electrostatic Force: The force between two charges at rest, described by Coulomb’s Law.
• Ampere: The unit of electric current in the International System of Units (SI), equivalent to one coulomb per second.
• Volt: The unit of electric potential difference and electromotive force in the International System of Units (SI), equivalent to one joule per coulomb.
• Ohm: The unit of electrical resistance in the International System of Units (SI), equivalent to one volt per ampere.
• Watt: The unit of power in the International System of Units (SI), equivalent to one joule per second.