Voltage measures the electric potential difference between two points in a circuit. It is the driving force that pushes charge carriers through the circuit.

Ohm's Law establishes the relationship between current, voltage, and resistance in an electrical circuit. This fundamental law is essential for solving basic circuit problems.

Electrical resistance is measured in Ohms. This unit quantifies how much a component impedes the flow of electrical current.

In a series circuit, the total resistance is the sum of all individual resistances. This cumulative effect increases the overall opposition to the current flow.

A resistor is used to control and limit the current in an electrical circuit by providing resistance. It is one of the basic components used for current regulation.

In a series circuit, resistances add up directly, so 4 ohms + 8 ohms equals 12 ohms. Applying Ohm's Law (I = V/R), the current is 12 V divided by 12 ohms, which equals 1 A.

When resistors are connected in parallel, the equivalent resistance is always lower than the smallest individual resistor. This occurs because the current has multiple paths to take, reducing overall opposition.

Using the power formula P = I²R, we solve for current: I = sqrt(P/R) = sqrt(20/10) = sqrt(2), which is approximately 1.41 A. This calculation demonstrates the relationship between power, current, and resistance.

Kirchhoff's Current Law is based on the conservation of electric charge. It asserts that the total current entering a junction must equal the total current leaving, ensuring charge balance within the circuit.

The voltage drop across a resistor in a divider circuit is directly proportional to its resistance compared to the total series resistance. This proportionality is the basis for designing voltage dividers in circuits.

Ohm's Law tells us that current is inversely proportional to resistance when voltage is constant. Therefore, if the resistance increases, the current decreases in a linear manner.

Connecting resistors in parallel creates multiple paths for current, thereby reducing the overall resistance. This is a fundamental concept in network analysis.

A node is a point in a circuit where components are interconnected. Recognizing nodes is crucial for applying methods such as nodal analysis in circuit theory.

Impedance is a comprehensive measure that includes both the resistance and the reactance of a circuit. It plays a key role in AC circuit analysis by describing the total opposition to current flow.

To determine the total resistance in complex circuits, one must reduce the circuit step-by-step by combining series and parallel resistor groups. This method ensures accurate calculation of the overall resistance.

When dealing with circuits that have multiple loops with shared components, independent KVL equations must be written for each loop. This method ensures that the voltage drop across the shared resistor is correctly accounted for in both loops.

A Wheatstone bridge is balanced when the ratio of resistances in one branch is equal to the ratio in the opposite branch. This balance results in a zero potential difference across the bridge, indicating no current flow through the detector.

Thevenin's Theorem simplifies circuit analysis by reducing a complex network to a single voltage source and a single series resistor. This equivalent circuit makes it easier to analyze and understand the behavior of the original circuit.

When batteries are connected in opposing directions, their voltages combine algebraically, meaning the net voltage is the difference between them based on polarity. This requires careful consideration of the direction of each battery's voltage.

In AC circuits, resistors maintain a constant impedance regardless of frequency. However, the impedance of capacitors and inductors is frequency dependent, which alters the overall impedance as the frequency changes.