series & parallel circuits Flashcards
which components are always connected in parallel?
voltmeter
series circuit
a circuit where the different components are connected in a line, end to end between the +ve and -ve of the power supply
what happens if one component is removed or disconnected in a series circuit?
the circuit is broken
cell potential difference in a series circuit
increases when more cells are connected in series-the pd adds up
total potential difference in a series circuit
total pd of the supply is shared between the components
V=V₁ + V₂
current in a series circuit
the same current flows through all components I₁=I₂
resistance in a series circuit
resistance adds up- the total resistance of two components is the sum of the resistance of each component
R=R₁ + R₂
why does resistance add up?-series
by adding a resistor, the two resistors have to share the total pd
why is current reduced with more resistors?-series
pd across each resistor is lower so the current through each resistor is also lower, current is the same everywhere so the total current is reduced and resistance increases
a bigger resistance
a bigger share of total pd
parallel circuit
each component is separately connected to the +ve and -ve of the supply
which component is always connected in series?
ammeter
what happens if you remove or disconnect a component?-parallel
it will hardly affect the others
potential difference in parallel
it is the same across all components V₁=V₂…
current in parallel
- total current through the whole circuit is the sum of the
currents through the separate components, shared across branches - It= I1 + I2 + …
what is the current is two identical components are connected in parallel?
the same current will flow through each
resistance in parallel
- adding a resistor reduces the resistance
- the total resistance of two resistors is less than the resistance of the smallest individual resistor
- 1/Rt = 1/R1 + 1/R2
why is resistance decreased with more resistors?-parallel
both resistors have same pd
pushing force making current flow is same as source pd for every resistor added
by adding another loop, the current has more than one direction to go in
increases total current that can flow around so resistance is decreased
