Is Current The Same In Parallel: 3 Important Explanations


In this article, we’ll discuss Is Current The Same In Parallel Or Not. The parallel connection is known to divide the circuit into branches. So the entire current gets divided into those branches.

Parallel circuits consist of one or multiple branches. When the total current enters one branch, it splits up into respective branches. The branch currents are lower than the total amount of current. The branch current values depend upon the branch resistance. So, the current is different in parallel circuitry.

Is Current The Same In Parallel?- Illustrate 

We know the current is different in parallel circuitry. Let us take an analogy to understand this phenomenon better. A person is rushing to reach the office as he is already late. There are two choices for him; A road with lesser traffic, and another road with heavy traffic jams. He will choose the first road as it’s less congested and less time-consuming.

An electron has multiple paths to flow in parallel. The electron selects the path with least opposition or resistance. This damages the circuit. Current splits according to the resistor value. These values vary with current inversely and decide the current in the paths. So, the current is distinct in parallel.

Read more on.. Is Voltage The Same In Parallel: Complete Insights and FAQs 

How to calculate current in a parallel circuit? Explain with a numerical example.

We use Ohm’s law to determine the quantity of current in parallel circuit configuration. We shall discuss the process with an easy mathematical illustration.

Is Current The Same In Parallel- circuit

Figure 1 shows a parallel electrical circuit with four resistive components with 5 ohms, 10 ohms, 15 ohms, and 20 ohms, respectively. The supply voltage is 30 Volts. Our target is to find the total circuit current i and all the values of current passing through the four resistors. It is already known to us that, in a parallel circuit, the total current gets more than one path to flow.

Hence, it gets divided into smaller components that pass through the resistors. In this example, initially, we shall measure the entire circuit current and afterward go on to calculate the currents through each resistor. 

So, the first stage is to know the equivalent network resistance. We know Req for parallel combination= product of four resistors/sum of products of resistors taking three at a time [Latex]=\frac{5\times 10\times 15\times 20}{5\times 10\times 15 + 10\times 15\times 20 + 15\times 20\times 5 + 20\times 5\times 10}=2.4 \; amp[/Latex]

The supply voltage is 30 Volts. 

The total current I = 30/2.4=12.5 amp

Now, we shall find the currents through the four resistors. We know the current passing through any resistor in a parallel network= supply voltage/ value of that resistor.

So, i1= 30/5 = 6 amp

i2= 30/10 = 3 amp

i3= 30/15 = 2 amp

i4= 30/20 = 1.5 amp

This is how we determine the current in any parallel circuit.

Is Current The Same In ParallelFAQs

Is current constant in parallel circuits?

The current flowing through every resistive component in a parallel circuit is neither the same nor constant.

We have previously described why it isn’t the same in parallel. It’s because of the division that occurs in branches with dissimilar resistance. Also, the current is not constant. The word ‘constant’ specifies a particular value. Just like the voltage, the current is also never a constant parameter. So, it cannot be said to be constant.

Compare the current measurements in series and parallel circuits with a mathematical example.

For this comparison, we shall take one parallel and one series combined circuits. Both the circuits contain three equal value resistors in respective configurations.

Figure 2 describes two circuits, one with series resistors, another with parallel resistors. All the three resistors in the series configured circuit are identical to those in the parallel configured circuit. Both the circuits receive 10 Volt supply voltage.

The equivalent resistance amount in series circuit = 2+4+8 = 14 ohm

So, I = 10/14 = 0.71 amp

The equivalent resistance amount in parallel circuit [Latex]=\frac{2\times 4\times 8}{2\times 4 + 4\times 8 + 2\times 8}=1.14 \; \Omega[/Latex]

So, I = 10/1.14 = 8.77 amp

If, i1, i2, and i3 are the currents for the 2 ohm, 4 ohm, and 8 ohm resistors respectively,

Then, for the series configuration, I= i1=i2=i3 = 0.71 amp

For the parallel configuration, i1 = 10/2 = 5 amp

i2 = 10/4 = 2.5 amp

i3 = 10/8 = 1.25 amp

From the above derivations, we can understand how the different current components are calculated in both circuits.

Why does current change in parallel circuit but not in series circuit?

Parallel circuitry contains more than one path for the current to pass whereas there is only one path for current in the series circuitry.

Whenever, current enters any parallel network, it has to split in the branches proportionately. On the other hand, series circuits don’t face this compulsion as it has only one way for current flow. This is why current changes in parallel but not in series circuits.

Calculate the equivalent resistance between A and B in the parallel network shown below.

The electrical network depicted in the above image is nothing but the conjunction of a few parallel circuits. We’ll divide them and calculate the required current.

We shall first find out the equivalent resistance of ABC network. AB and BC are series connected resistors, so the equivalent resistance is 2+2= 4 ohm. This gets added to AC in parallel and becomes 4/2= 2 ohm. So now the network is reduced to figure 3.

We can further calculate similarly and get the following stages. Thus, finally the equivalent resistance obtained = 2 || 4 = 8/6 = 1.33 ohm.

When Is Current The Same In Parallel?

There is only one case when the branch currents in parallel circuitry can be identical. Let us discuss this with a general circuit configuration.

In the circuit portrayed above, we can see a parallel network comprising some resistors. The voltage supplied is V. We need to calculate the total current as well as the branch currents and compare between them. Let us first determine the total current.

So, total current I=V/Req = 3V/R

Req= Equivalent resistance of the network= R3/ (R2+ R2+ R2) = R/3

Now, we’ll see the value of three individual resistor currents. 

Current through the component R1=i1= V/R1= V/R

Current through the component R2=i2= V/R2= V/R

Current through the component R3=i3= V/R3= V/R

Hence, we can observe that i1=i2=i3

Therefore, we can come to a conclusion that if the values of all branch resistors are the same, they will have the same amount of current flowing through them.

From this example, we can also derive a general formula that if a parallel network has N identical resistors, the equivalent resistance of such a network will be= the value of any resistor/N

Kaushikee Banerjee

I am an electronics enthusiast and currently devoted towards the field of Electronics and Communications . My interest lies in exploring the cutting edge technologies. I'm an enthusiastic learner and I tinker around with open-source electronics. LinkedIn ID- https://www.linkedin.com/in/kaushikee-banerjee-538321175

Recent Posts