serries parallel circuit

Last lecture I was discussing about parallel circuit and special case of parallel circuit. This lecture I discussing about series parallel circuit. Actually it’s the combination of series and parallel circuit.

Here I use a simple circuit to learn series-parallel circuit. Mention that R2 and R3 are connected in parallel with each other and that both together are connected in series with R1.

series parallel circuit

One simple rules to solve such circuit is to first reduce the parallel branches to an equivalent series circuit and then solve the circuit as a simple series circuit.at the right side

RT for parallel combination = (R2*R3)/ (R2+R3)

Total circuit resistance =R1+ (R2*R3)/ (R2+R3)

Voltage across parallel combination =I*(R2*R3)/ (R2+R3)

I think now you can find out the value of I1, I2, and I3 easily.

for enlarge this picture click on the picture

Application of series-parallel circuit:

 1. In an automobile, the staring, lighting and ignition circuit are all individual circuits joined to make a series-parallel circuit its power from one battery.

2. Power supplies are connected in series to get a higher voltage and in parallel to get a higher current.