Current Electricity Concepts and Formulas

These flashcards cover key terms and concepts related to current electricity, including definitions, laws, and formulas essential for understanding the topic.

Electric Current (I)

The flow of charge per unit time, or the rate of flow of charge.

Potential Difference (V)

The energy transferred per unit charge between two points in a circuit.

Resistance (R)

A measure of how difficult it is for charge carriers to pass through a component, defined by R = V/I.

Ohm's Law

States that for an ohmic conductor, current is directly proportional to the potential difference across it.

Ohmic Conductor

A component that follows Ohm’s law, represented by a straight line graph through the origin on a current-voltage graph.

Semiconductor Diode

A component whose current-voltage graph shows characteristics related to forward and reverse bias.

Filament Lamp

A component whose resistance increases with current, leading to a curved current-voltage graph at higher currents.

Resistivity (ρ)

A measure of how easily a material conducts electricity, defined as ρ = (R * A) / L.

Superconductor

A material that has zero resistivity below a certain critical temperature.

Power (P)

The energy transferred over time, defined by the formula P = E/t.

Series Circuit

In this type of circuit, the total resistance is the sum of individual resistances, and current is the same throughout.

Parallel Circuit

In this type of circuit, the potential difference across each branch is the same, and the total current is the sum of branch currents.

Kirchoff's First Law

The total current flowing into a junction is equal to the total current flowing out.

Kirchoff's Second Law

The sum of all the voltages around a closed loop in a circuit is equal to zero.

Electromotive Force (emf)

The energy transferred by a cell per coulomb of charge, represented as ε = E/Q.

Terminal Potential Difference (V)

The potential difference across the load resistance in a circuit.

Lost Volts (v)

The potential difference across the internal resistance of a battery, representing energy wasted.