Types of Circuits: Series and Parallel Circuits
SERIES CIRCUITS
Description A series circuit offers only ONE path for the
current to travel.
As a result:
✓ There is ONE shared pathway for
electrons to travel.
✓ The force pushing the charges
through the wire must be split
amongst all loads, so the voltage is
divided among the loads
✓ As more bulbs are added, the
brightness of each bulb decreases
✓ If one bulb burns out, all other bulbs
turn off
PARALLEL CIRCUITS
A parallel circuit is a circuit which offers
multiple pathways for electric charge to flow,
such that each load is connected directly to the
power source.
✓ Each bulb shines with equal brightness
because it receives the full potential of
the power source.
✓ If one bulb burns out, the others stay on.
Schematic
Voltage
voltage is divided among the loads
Voltage is NOT divided. Each load receives the full
potential of the power source.
V1 = V2 = V3 = …….
VTotal = V1 + V2 + V3 + ……
Current
The current (Amperes) is the same for every
load since all the electrons must travel the
single pathway provided by a series circuit.
✓ Current is split between the loads.
The flowing charges have to divide
themselves between each branch in
the parallel circuit:
I1 = I2 = I3 = …….
Resistance
Resistance is the same through each resistor.
Equivalent (total) resistance is the sum of all
resistances:
ITotal = I1 + I2 + I3 + ……
Equivalent (total) resistance is always lower than
every individual resistor:
𝟏
Req = R1 + R2 +R3 + ……
𝑹𝒆𝒒
=
𝟏
𝑹𝟏
+
𝟏
𝑹𝟐
+
𝟏
𝑹𝟑
+…