Electrical Circuits Flashcards
What is needed for charge to flow through a closed circuit?
A source of potential difference.
What is electrical current?
Current is the flow rate of charge.
How is current shared in series and parallel circuits?
It is the same throughout in series circuits, and is split in parallel circuits.
What does it mean for a conductor to be ohmic?
The current through an ohmic conductor (at a constant temperature) is directly proportional to the potential difference across the resistor. This means that the resistance remains constant as the current changes.
What is a diode?
The current through a diode flows in one direction only. The diode has a very high resistance in the reverse direction.
How do the resistances of filament lamps, thermistors, and LDRs change?
The resistance of a filament lamp increases as the temperature of the filament increases. The resistance of a thermistor decreases as the temperature increases. The resistance of an LDR decreases as light intensity increases.
How is potential difference shared in series and parallel circuits?
In a series circuit, potential difference is shared. In a parallel circuit, it is equal across each branch.
How is total resistance calculated in series and parallel circuits?
In a series circuit, total resistance is the sum of individual resistances. In a parallel circuit, the total resistance is less than the smallest individual resistance, calculated by the reciprocal of the sum of the individual reciprocals.
