Basic Electrical Quantities and Ohm's Law

Basic Electrical Quantities

• Electric Current (I): The rate of flow of electric charge. Measured in Amperes (A). One Ampere is equivalent to one Coulomb of charge flowing per second.
• Electric Potential Difference (V): The difference in electrical potential energy per unit charge between two points in a circuit. Measured in Volts (V). It drives the flow of current.
• Electric Charge (Q): A fundamental property of matter. Measured in Coulombs (C). Charge can be positive or negative.
• Electric Resistance (R): Opposition to the flow of electric current. Measured in Ohms (Ω). Materials with high resistance impede current flow more than those with low resistance.
• Electric Power (P): Rate at which electrical energy is transferred. Measured in Watts (W). Power is the product of voltage and current (P = V * I).

Ohm's Law

• Ohm's Law describes the relationship between voltage, current, and resistance in a simple circuit: V = I * R.
• If resistance stays constant, increasing voltage increases current proportionally.
• If voltage remains constant, increasing resistance decreases current.

Electrical Circuits

• Series Circuit: Components connected end-to-end. Current flows through each component sequentially.
• Parallel Circuit: Components connected across each other. Each component has its own branch. Voltage across each component is the same.
• Combination Circuit: Circuit with both series and parallel components. Analysis uses both series and parallel circuit principles.

Conductors and Insulators

• Conductors: Materials allowing easy electric current flow. Examples include copper and aluminum.
• Insulators: Materials resisting current flow. Examples include rubber, plastic, and glass.

Kirchhoff's Laws

• Kirchhoff's Current Law (KCL): Sum of currents entering a junction equals the sum of currents leaving that junction. This reflects charge conservation.
• Kirchhoff's Voltage Law (KVL): Sum of voltage drops around any closed loop in a circuit is zero. This reflects energy conservation.

Alternating Current (AC) and Direct Current (DC)

• Direct Current (DC): Current flows in one direction. Batteries are a primary source of DC.
• Alternating Current (AC): Current reverses direction periodically. Power grids typically use AC for transmission.

Basic Electrical Components

• Resistor: Component introducing resistance into a circuit.
• Capacitor: Component storing electrical energy in an electric field.
• Inductor: Component storing electrical energy in a magnetic field.
• Diode: Component allowing current flow in one direction only.
• Transistor: Semiconductor device amplifying or switching electronic signals and electrical power.

Power and Energy in Electrical Circuits

• Energy (E): Capacity to do work. Calculated as the product of power and time (E = P * t).
• Power Dissipation: Rate of converting electrical energy into heat in a resistor. Calculated using P = I²R or P = V²/R. Heat is often an unwanted byproduct, but usable in heat lamps and furnaces.

Explore essential concepts in electrical engineering including electric current, potential difference, charge, resistance, and power. This quiz covers fundamental principles such as Ohm's Law and its applications in circuits. Test your knowledge on the key relationships that define electrical systems.