Parallel circuit or parallel connection means when two or further electrical devices are linked together in side by side like arrangement within a circuit. In this connection, every device is located in its own distinct branch. Voltage, we can say that it is the reason for the current to pass throughout a closed circuit. In this article, we can discuss in detail about the voltage in parallel circuit.
Now, the multiple branch lines in a circuit means there are several pathways for the charge to move to the external circuit. When a charge reaches a node or branching location, it makes a selection as to which branch should it pass through on its ride to reach back to the low potential terminal.
Let us consider a closed circuit of a voltage source and a resistor. In this circuit, the current will flow through the single pathway available. Next, in the same circuit we add two further resistors in parallel with the first resistor. It results in multiple pathways for the current to pass through rather than a single pathway to reach the low potential terminal. So, with the increase in number of branches, the overall resistance decreases and it is obvious that the current in the circuit increases. That is, the entire current will be the sum total of the different currents through the three resistors. Here in the parallel circuit, we can see that there are at most two sets of electrically common points. That is; A and H, B and G, C and F, D and E in the circuit shown below. Voltage, which is measured across the common points for all time, should be equal.
In the above two figures, first shows the close circuit with a voltage source and a single resistor. Second one is the parallel circuit of 3 resistors and a voltage source.
The voltage in this circuit is same for each and every three branches and it is also same as the voltage of the source. That is
The total current in this given parallel circuit is represented by Itotal and is given as
The total or effective resistance of this given parallel circuit is
Thus, we can conclude that by adding additional branches in a particular parallel circuit, the total current will get increased and the circuit get overloaded.
Advantages of Parallel Circuits
When we want to connect two bulbs to a single battery, there are two options for us. Either it can be connected in an array or in parallel. If we connect it in an array, the two bulbs will be in the single and same conducting path between the two terminals of the battery. The problems with this connection are the following
- We cannot turn on or operate one bulb.
- Both the bulbs will be dim since they are using the same source.
- If there is a fault in one bulb, then the whole circuit will be affected.
Next, if we are connecting the two bulbs side by side or in parallel, the two bulbs will get the full voltage of the battery. So the result will be the following advantages.
- Both bulbs get full amount of voltage in the battery.
- We can operate two bulbs separately.
- Both the bulbs will be bright when turned on.
- If there is a fault in one bulb, it can be removed or repaired. Thus, the whole circuit will not be affected.
Parallel Circuits in Home
All our appliances in home are connected in parallel with each other. That is why we can operate every appliance separately without affecting other. For example, we can turn on washing machine without turning on microwave or television as well.
We know that in our house, the electrical cables comprises of three wires- live, neutral and earth. For this moment we are ignoring the earth and simply concentrate on live wire and neutral wire. The voltage is present across the live and neutral wire which is connected ultimately to a power plant. Each and every socket in our house is linked to these live and neutral. When we plug in a metal pin of an appliance into this socket, it creates an electrical connection with this socket. Every appliance possesses its own connection among the live and neutral wire. So, when we switch on the device, the whole voltage will be present across it and it can be operated separately.
Application of Voltage in Parallel
- House hold appliances.
- Lighting circuits.
- Power ring.
- Parallel capacitors etc.