Glossary
Circuit Analysis
The process of determining the unknown electrical quantities (like currents, voltages, and resistances) in a circuit using fundamental laws and principles.
Example:
Using Kirchhoff's rules and Ohm's law to find all currents and voltage drops in a complex network is a form of circuit analysis.
Electric Potential Energy ($\Delta U_E = q \Delta V$)
The energy a charge possesses due to its position in an electric field. The change in this energy is given by the product of the charge and the change in electric potential.
Example:
When a 2 Coulomb charge moves across a 6 Volt potential difference, its electric potential energy changes by 12 Joules.
Electric Potential Graph
A graphical representation showing how the electric potential (voltage) changes as one traverses different points or components within an electrical circuit.
Example:
An electric potential graph for a simple series circuit would show a sharp upward jump at the battery and gradual downward slopes across each resistor.
Energy Conservation
A fundamental principle stating that energy cannot be created or destroyed, only transformed. In circuits, it means the total energy gained by a charge in a loop equals the total energy lost.
Example:
A charge moving through a circuit gains energy from a battery, and then this energy is conserved as it is dissipated as heat in resistors or used by other components.
Kirchhoff's Loop Rule
A fundamental principle stating that the sum of all voltage changes (potential differences) around any closed loop in an electrical circuit must equal zero.
Example:
When analyzing a series circuit with a battery and two resistors, applying Kirchhoff's Loop Rule ensures that the voltage supplied by the battery equals the sum of voltage drops across the resistors.
Loop Rule Equation ($\sum \Delta V = 0$)
The mathematical expression of Kirchhoff's Loop Rule, stating that the algebraic sum of all potential differences around any closed circuit loop is zero.
Example:
To find an unknown current in a multi-loop circuit, you would set up an equation like using the Loop Rule Equation.
Voltage Changes / Potential Differences
The difference in electric potential between two points in a circuit, representing the work done per unit charge to move a charge between those points.
Example:
As current flows through a resistor, there's a voltage change (or potential difference) across it, indicating energy loss.
Voltage Drop (across resistor)
A decrease in electric potential experienced by charges as they pass through a resistor, where electrical energy is converted into thermal energy.
Example:
If 2 Amperes flow through a 5 Ohm resistor, there will be a voltage drop of 10 Volts across it.
Voltage Gain (from battery)
An increase in electric potential experienced by charges as they pass through a voltage source like a battery, where chemical energy is converted into electrical potential energy.
Example:
A 9V battery provides a voltage gain of 9 volts to charges moving from its negative to its positive terminal.