Parallel Circuits
A parallel circuit is a circuit in
which the current has more than one path to flow. The same voltage is applied
across each branch. If the load resistance in each branch is the same, the
current in each branch will be the same. If the load resistance in each branch
is different, the current in each branch will be different. If one branch is
broken, current will continue flowing to the other branches.
a.
Practical view; b. Electronical view
The switch has the role to provide current to the
circuit so that the other components can function properly. And the power
supply has the principal role to generate energy for the circuit.
A
Parallel Circuit has multiple paths or branches to ground. Therefore:
in the event of an open in the circuit in one of the
branches, current will continue to flow through the remaining;
each branch receives source voltage;
current flow through each branch can be different;
the resistance of each branch can be different.
In
parallel connection, two or more resistances (R1, R2,
etc.) are connected in a circuit as follows, with one end of each resistance
connected to the high (positive) side of the circuit, and one end connected to
the low (negative) side. Full battery voltage is applied to all resistances
within a circuit having a parallel connection.
Resistance R0 (a combination of resistances R1 and R2) in a parallel connection can be determined as follows:
From the above, the total current I flowing in this circuit can be determined from Ohm's law as follows:
The
total current I is also equal to
the sum of currents I1
and I2 flowing
through individual resistances R1 and R2
Since battery voltage V is applied equally to all resistances, the strength of currents I1 and I2 can be determined from Ohm's law as follows:
