The sum of all potential differences (voltages) around any closed loop in a circuit must equal zero: $\sum \Delta V = 0$

The change in electric potential energy per unit charge when a charge moves between two points.

The energy a charge possesses due to its position in an electric field.

A continuous path in a circuit that starts and ends at the same point, allowing current to flow without interruption.

The decrease in electric potential across a circuit element, typically a resistor, due to the energy dissipated as current flows through it.

For a constant voltage source, increasing resistance will decrease the current in the loop, according to Ohm's Law.

A voltage source provides a potential rise, driving current through the loop and influencing the potential drops across other components.

This violates the conservation of energy, indicating an error in the circuit analysis or an external energy source/sink not accounted for.

The direction of the current in the loop will reverse, and the voltage drops across resistors will also change direction.

The brightness of the light bulb increases because the power dissipated by the resistor (light bulb) is proportional to the square of the current ($P = I^2R$).

Loop Rule: Applies to closed loops, based on energy conservation. Junction Rule: Applies to junctions, based on charge conservation.

Voltage: Electric potential energy per unit charge. Electric Potential Energy: Energy a charge has due to its position in an electric field.

Voltage Source: Provides a potential rise (ideally). Resistor: Causes a potential drop due to energy dissipation.

Series: Only one loop, so one application of the loop rule is sufficient. Parallel: Multiple loops, requiring multiple applications of the loop rule to solve for all unknowns.

Electric Potential: The potential energy per unit charge at a specific point in an electric field. Electric Potential Difference: The change in electric potential between two points.