Electrical Circuits Flashcards
What is an electric current
Flow of electric charge
How do you work out the potential difference (voltage)
Work done (energy transferred) per coulomb of charge (q)
What are current potential difference graphs used to show
How the current through a component varies with the potential difference across it
What does a current potential difference graphs for a resister at a constant temperature show
The current through a resister (at a constant temperature) is directly proportional to the potential difference across the resister
How can the resistance of a component be found
Measuring current through, and potential difference across, the component
What does a current through a component depend on
The resistance
The greater the resistance in a component….
The smaller the current for a given potential difference.
What is the potential difference provided by cells connected in a series
The sum of the potential difference of each cell (depending on the direction in which they are connected)
What 3 factors are there in components connected in a series
The total resistance is the some of the resistance in each component
There’s the same current through each component
The total potential difference of the supply is shared between the components
What 2 factors are there for components connected in a parallel circuit
The potential difference across each component is the same
The total current through the whole circuit is the cum of the currents through the separate compounds
What does the resistance of a filament light bulb do
Increases as the temperature of the filament increases
What does the current through a diode do and what effect does it have on the resistance
Flows in one direction only however has very high resistance in the opposite direction
What does an led do
Emits light when a current flows forward in it
The resistance of a light dependent resister (LDR) increases as…
The light intensity increases
The resistance of a thermistor decreases as
The temperature increases
