Electric Definitions

This set of flashcards contains key terms and definitions related to electric circuits for Edexcel Physics A Level, aiding in exam preparation.

Conventional Current Flow

Flow of current from positive to negative; used to describe current direction in a circuit.

Current

The rate of flow of charge in a circuit, measured in Amperes, symbol 'I'.

Detecting Circuit

A circuit with a potential divider where a semiconductor alters resistance and voltage based on external conditions.

Diode

Component that allows current to flow in one direction; has a threshold voltage (typically 0.6 V) for normal current flow.

Electromotive Force (EMF)

Energy supplied by a source per unit charge passing through it, measured in volts.

Electron Flow

The flow of electrons in a circuit from negative to positive.

Internal Resistance

Resistance within a power source that impedes current flow and dissipates energy.

Kirchoff’s First Law

Total current entering a junction equals total current leaving it.

Kirchoff’s Second Law

The sum of EMF in any loop equals the sum of potential differences across all components.

Light Dependent Resistors (LDR)

Components whose resistance decreases as light intensity increases.

Ohmic Conductor

A conductor that follows Ohm's law, where current is directly proportional to potential difference.

Ohm’s Law

Electric current is proportional to potential difference and inversely proportional to resistance.

Parallel Connection (Parallel Circuit)

Two electrical components on separate loops in a circuit with the same potential difference and split current.

Potential Difference

Difference in electrical potential between two points; work needed per coulomb to move charge, measured in Volts.

Potential Divider

Combination of resistors in series that splits potential difference into a specific ratio.

Power

Rate of energy transfer in a circuit, calculated as current multiplied by potential difference, measured in Watts.

Resistance

Measure of how difficult it is for current to flow, measured in Ohms, symbol 'R'.

Resistivity

Measure of how difficult it is for charge to travel through a material, depending on its area, length, and resistance.

Semiconductors

Materials that change resistance based on external conditions.

Series Connection (Series Circuit)

Two electrical components on the same loop in a circuit, splitting potential difference depending on resistance.

Superconductor

Material with zero resistivity below a critical temperature, used for efficient electricity transmission.

Terminal Potential Difference

Actual potential difference across a power source's terminals, equals EMF minus internal resistance drop.

Thermistor

Component whose resistance decreases with an increase in temperature.

Variable Resistors

Resistor with adjustable resistance, typically used to change circuit voltage.

Voltmeter

Device used to measure potential difference with ideally infinite resistance to prevent current passage.