Current Electricity I Flashcards
voltage =
the amount of energy transferred per coulomb of charge
1 volt is …
1 joule of charge
voltage =
energy / charge
current =
the rate of flow of charge
what can be used to indicate the presence of current in a circuit?
lamps and LEDs
the effect of changing the resistance on the current in a circuit …
increasing the resistance will decrease the current. This can be achieved by adding more components or components with a higher resistance. The reverse can be done to decrease the resistance
How to LDRs work :
resistance changes with intensity of light. The brighter the light, the less resistance. The dimmer the light, the more resistance.
How do thermistors work:
resistance changes with temperature. In hot conditions there is less resistance. In cold conditions there is more resistance
Q stands for
charge
I stands for
current
T stands for
time
current =
`charge / time
potential difference =
amount of work done (energy transferred) per unit charge
Current in series circuits depend on …
the applied voltage and the number and nature of other components
In a series circuit …
everything is connected in one line. This means the voltage is shared out between each component; this makes it useful for supplying low power things like fairy lights
In a parallel circuit …
different components are connected separately to the supply. This means that if one component breaks down the others can be powered as the whole circuit is still functioning. Is is also good for charging higher power things as the potential difference is equal all over a parallel circuit so each component receives the full voltage.
