Electric Circuits Flashcards
Conventional current
Flow from positive to negative.
Used to describe direction of current in a circuit
Current
Rate of flow of charge in a circuit
Detecting circuit
Circuit with a potential divider where one resistor is a semiconductor that changes resistance with external conditions causing the voltage across the other resistor to change
Diode
Components that allow current through in one direction
EMF, electromotive force
Energy supplied by a source per unit charge passing through the source, measured in volts
Electron flow
Flow of electrons from negative to positive in a circuit
Internal resistance
Resistance any power source has that makes it harder for current to flow through the source, causing energy to dissipate
Kirchhoff’s First Law
Total current entering a junction is equal to the total current leaving it
Kirchhoff’s Second Law
Sum of EMF in any loop of the circuit is equal to the sum of the potential differences across each component
LDR, light dependent resistor
As light intensity increases, resistance of the component decreases
Ohmic conductor
Conductor that follows Ohm’s law when kept at a constant temperature
Ohm’s Law
I = V/R
Parallel connection
In a parallel circuit, potential difference in each loop is the same and current is split between branches
Potential difference
Difference in electrical potential between two points in a circuit
Work done required per coulomb to move charge from lower to higher potential
Potential divider
Combination of at least 2 resistors in a circuit that results in potential difference being split into the ratio of the resistance of the resistors
Power
Rate of energy transfer in a circuit
Resistance
Measure of how difficult it is for current to flow in a circuit or component
Resistivity
Measure of how difficult it is for charge to travel through a material
Semiconductor
Materials that change their resistance depending on external conditions
Series connection
In a series circuit, potential difference is split between components depending on resistance and current is the same across all components
Superconductor
Material that has zero resistance below a critical temperature
Terminal potential difference
Actual potential difference across the terminals of a power source
V = (R-r) x I
V = EMF - Ir
Thermistor
As temperature increases, resistance decreases
Variable resistor
Resistor that can have its resistance changed
