1. A circuit with several resistances but only one conducting path.
SERIES CIRCUITS
SERIES CIRCUITS
A circuit with several resistances but only one conducting path.
A circuit with several
resistances but only one conducting path.

2. SERIES CIRCUIT FORMULA’S
Req= R1 +R2 + R VT = V1+V2 +V3
IT = I1 =I2 =I Req- equivalent resistor
If one resistor goes out, all three go out.

3. EXAMPLE
A toaster of 60Ω, a lamp of 80Ω and a hair dryer of 100Ω are connected in series across a potential difference of 120V. Find the total resistance and current in the circuit.
RT= R1 +R2 + R3
RT= 60Ω + 80Ω + 100Ω
RT= 240Ω
RT = VT / IT
240Ω = 120V/ IT
IT = 0.50Amps

4. b) Find the drop in potential across each resistor.
R1=V1/I R2= V2 / I2
60Ω =V1/ 0.5Amp Ω = V2 / 0.5Amp
V1= 30V V2= 40V
R3 = V3 / I3
100Ω = V3 / 0.5Amp
V3 = 50V
CHECK: VT = 30V + 40V + 50V = 120V √

5. c) Draw a circuit diagram
V1=30V
I1= 0.5 Amp
= 60Ω
VT =120V
RT=240Ω
IT=0.5Amp
= 80Ω
V2 = 40V
I2 = 0.5Amp
= 100Ω
V3= 50V
I3 = 0.5Amp