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Normally we use the Kirchhoff Laws on “loops” in the circuit and to form loops, “electronic components” are connected to wires on both sides. However, with a ground connection there’s only one side connected to the circuit by wire. This makes them seem outlying.

Example:

Enter image description here

Find the current through the cells, and the potential difference between each cell.

$\scriptsize\text{Note: I use quotes, “ ”, for unfamiliar physics terminology… Maybe there are mistakes.}$

Peter Mortensen
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youthdoo
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Since there's no other connection to ground in the circuit, then this connection to ground has no effect on the loop currents, so it can be ignored for loop or mesh analysis. Its only effect on node voltages is to tell you which node to use as the reference. It doesn't change the potential difference between any two nodes in the circuit.

If there were another ground connection in the circuit, then of course it could cause another loop to be formed, which must be considered for loop or mesh analysis. In this case it is a good idea to draw the connections between ground symbols explicitly to be sure you haven't missed a loop in your analysis.

The Photon
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  • I'll accept this answer later but not now because the tick button doesn't work when the internet is bad, sorry. – youthdoo Aug 30 '22 at 16:03
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For KCL, ground is no different than any other node: the sum of the currents into ground must be zero. So, in this case, there is zero current through ground.

For KVL, without ground you get to choose which node is 0V. By convention, ground is 0V, so by connecting ground, you've made the choice.

John Doty
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What you call the "ground connection" is simply assigning a node as being zero potential. It is irrelevant to determine the loop current in your diagram since only potential differences and not absolute potentials are relevant.

However, if you were doing Kirchhoff node analysis instead of loop analysis, where the objective is to determine the voltages at different nodes instead of currents in loops, then it is necessary to assign some node as being zero potential.

Hope this helps.

Bob D
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You can usually treat that ground connection as a open circuit (no current), that provides you with an offset for the absolute value of the potential (voltage) in the circuit.

The point connected to the ground and the ground itself has the same potential, here assumed to be $0 \, V$.

Remember that potentials (and thus voltage) are defined up to an additive constant, and the physics is independent on that since the physical quantities are related to the derivatives of the potentials.

basics
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    Open circuit? If there's more than one ground connection current may flow between them. – John Doty Aug 30 '22 at 14:31
  • Very large resistance between two ground connections, if not connected by conductive elements and far enough, and low voltages. Approximately you can close the circuit with infinite resistance elements, and thus they behave as open circuits. – basics Aug 30 '22 at 14:36
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    Conventionally, "ground" is a node at zero potential. Thus the voltage difference between ground connections is 0. Then, by Ohm's law, the resistance between two "ground" connections must generally be 0. As with any circuit node this is an idealization. – John Doty Aug 30 '22 at 14:43
  • Take a tension generator, connect it to two wires with the other ends grounded. What happens? Not controversy at all, just to improve the interpretation of physical process – basics Aug 30 '22 at 14:49