# How to calculate using mesh method when there's a current source and a resistor between two meshes

I'm trying to get the current in the 3 ohm resistor using mesh analysis. Forget about thevenin's theorem here.

However, what I know is that if there's a current source between two meshes then we do the supermesh analysis. But in this case there is a resistor and a current source in between the two meshes, which means we can't do the supermesh.

Here's the circuit:

So how do I get the current throught the 3 ohm resistor using the mesh method in this case?

I'm not asking for the final answer but how do I move on when a current source and a resistor are between 2 meshes ? Should the 3 ohm resistor take all the value of the current source(which means that the value of the current through the 3 ohm resistor is 5A)? Any help will be much appreciated :)

You should treat the circuit as if the current source and the components in series are not there in the first steps.
Then, relate the meshes with the current source like you use to do when the is just a current source without components in series with it.

Note that a current source can have any voltage across is, so the voltage drop across components in series with the current source is not relevant as it will not affect the circuit.
(And the current is of course dictated by the current source.)
That explains why you can leave those series components out together with the current source.

• so you mean i have to do the supermesh analysis? i didn't 100% get your point. If i should relate the meshes with only the current source without components in seires means i can do the supermesh then(no more resistor in series with the current source). Apr 5, 2020 at 20:13
• @AhmadBenos Yes, do the supermesh analysis, and when removing the current source like you use to do, remove the components in series with that current source as well. Apr 5, 2020 at 20:15
• Reason: The series resistor of 2 ohm has no effect: it does not determine the current (because the current source dictates the current) and it does not determine a voltage in the rest of the circuit (because a current source can have any voltage across it) Apr 5, 2020 at 20:17
• and after i do the supermesh ? what do i do next ? do the common source equation which is: (the current of the right mesh) - (current of the left mesh) = 5. So what i understood is that i do normal supermesh and ignore that resistor in series without the current source ? Apr 5, 2020 at 20:18
• @AhmadBenos exactly Apr 5, 2020 at 20:29

Simply consider the potential accross the branch consisting of the current source and the 2 ohm resistor as , say, V. Now proceed with mesh analysis. Eliminate the V to get your required answer.