A simple parallel circuit is a circuit containing more than one path for the flow of electric charge (current).
Here's what we know about parallel circuits:
The voltage drop is the same across each branch of a simple parallel circuit.
If there is only one voltage source (battery) in a parallel circuit, the voltage drop across each branch of the circuit must be equal to the voltage across the voltage source (battery).
The total current in a simple parallel circuit is divided among its branches, and the total current in a simple parallel circuit can be found by adding the currents in all of its branches.
The current in each branch can be found by dividing the voltage drop across the branch by the resistance of the branch.
As the number of branches increases, the equivalent (total) resistance of a simple parallel circuit decreases. Thus, the equivalent (total) resistance of a parallel circuit is less than the resistance of any one of its branches.
The equivalent (total) resistance of a simple parallel circuit can be found with the following equation:
1 / (equivalent resistance) = 1 / (resistance of branch 1 ) + 1 / (resistance of branch 2) + 1 / (resistance of branch 3) + ...
Simple Parallel Circuit With Two Branches--This is a parallel circuit because current has more than one pathway through the circuit. For this two-branch parallel circuit, current can take either of two paths. Note: This particular parallel circuit has three batteries. Not all parallel circuits have more than one battery. In fact, the number of batteries has nothing to do with whether the circuit is a series or a parallel circuit.
Simple Parallel Circuit With Three Branches--This is a parallel circuit because current has more than one pathway through the circuit. For this three-branch parallel circuit, current can take any one of three paths. Note: This particular parallel circuit has three batteries. Not all parallel circuits have more than one battery. In fact, the number of batteries has nothing to do with whether the circuit is a series or a parallel circuit.