Current Electricity Cheat Sheet

Key Definitions

• Current (I): The rate of flow of electric charge. ✅

• Voltage (V): Electric potential difference between two points. ✅

• Resistance (R): Opposition to the flow of current. ✅

• Ohm's Law: Relationship between voltage, current, and resistance. ✅

Important Concepts

Circuit Components

• Resistors: Devices that resist current flow.

• Capacitors: Store electrical energy in an electric field.

• Inductors: Store energy in a magnetic field.

Series and Parallel Circuits

• Series: Same current flows through all components. Total resistance is R_total = R1 + R2 + .... ✅

• Parallel: Voltage is the same across all components. Total resistance is 1/R_total = 1/R1 + 1/R2 + .... ✅

Key Formulas

• Ohm's Law: V = I * R

• Power: P = V I or P = I^2 R or P = V^2 / R

• Energy: E = P * t

Common Mistakes to Avoid

Common Mistake: Confusing series and parallel resistances. Remember series adds resistances while parallel decreases total resistance.

Memory Tricks

Tip: "VIR" — Voltage = Current x Resistance

Key Diagrams

Series Circuit:        Parallel Circuit:
  ----R1----R2---        ----R1----
 |                  |    |        |
 |                  |    |        |
 +--------V--------+    +--------V--------+