Resistor

Definition

A resistor is an electrical component that limits or regulates the flow of electrical current in a circuit. It provides resistance, measured in ohms ($\Omega$), to control voltage and current levels.

5 Must Know Facts For Your Next Test

1. The total resistance in a series circuit is the sum of all individual resistances: $R_{total} = R_1 + R_2 + ... + R_n$.
2. In a parallel circuit, the inverse of the total resistance is the sum of the inverses of each individual resistance: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + ... + \frac{1}{R_n}$.
3. Ohm's Law, $V = IR$, relates voltage (V), current (I), and resistance (R).
4. Resistors can be used to control voltage drops and divide voltages within circuits.
5. Power dissipation in a resistor is given by $P = I^2R$ or equivalently $P = \frac{V^2}{R}$.

Review Questions

• How do you calculate the total resistance of resistors connected in series?
• Explain how Ohm's Law relates voltage, current, and resistance.
• What is the formula for power dissipation in a resistor?

Related terms

Ohm's Law: A fundamental principle stating that the current through a conductor between two points is directly proportional to the voltage across the two points: $V = IR$.

Capacitor: An electrical component used to store energy electrostatically in an electric field. It consists of two conductors separated by an insulator.

Series Circuit: A type of electrical circuit in which components are connected end-to-end so that current flows through each component without branching.