Circuits Flashcards
1
Q
In series circuits…
A
- the more cells, the higher the potential difference
- potential difference is shared between all components
- there is only one loop, if your remove a component the circuit is broken
- the same current flows through the entire circuit
- total resistance is the sum of the resistance of all resistors in the circuit
2
Q
In parallel circuits…
A
- each component is connected separately except ammeters which connect in series
- if you remove one component it will hardly affect the others
- potential difference is the same across all the components
- current is shared between each loop, sum of current in each loop = total current of circuit
- adding loops and components decreases total resistance
3
Q
What is ohms law
A
V = IR
Voltage = current x resistance
- if V and I are directly proportional, R stays constant
4
Q
What does ohms law state
A
The current through a conductor is directly proportional to the potential difference across it
- only relevant at constant temperatures
5
Q
What are ohmic conductors
A
Electric conductors that obey Ohm’s law
- fixed resistors
- wires
- heating elements
* make a straight line through origin when plotted on an IV graph
6
Q
What are non ohmic conductors
A
Don’t follow Ohm’s law
- filament lamps
7
Q
Why are filament lamps non ohmic
A
- their current and potential difference aren’t directly proportional, this is because the resistance of the lamp increases as it’s temperature increases