Electronic – Ohm’s law of a circuit which has both a voltage source and current source


The voltage source has a specific voltage through it regardless of the circuit's current and its resistance while the current source has a specific current through it regardless of the voltage through it and its resistance.

My question is:

When there's a circuit which has both a voltage source and a current source with a load, a resistor R for example. How can people apply Ohm's law on it. The sum of both voltage and current must be reserved.

For example, the circuit has a current source and a voltage source connected in a series with a single resistor which

  • The voltage source supply 10V
  • The current source supply 3A
  • The resistance of the resistor is 4 ohm.
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How can Ohm's law be applied in this case.

If we take 10V then the current will be 2.5A which is lack of 0.5 A to make the sum of current equal 3 as the current source supply while if we take the current through it is 3 A then the voltage through it wil be 12 V that over the one which voltage source can supply. I have seen many circuit which have both of these source without knowing how to apply Ohm's law on it.

Best Answer

This only answers one part of your question, but I think it might be the main place where you are misunderstanding.

How can the Ohm Law be applied in this case?

"Ohm's Law" isn't a law for all circuits. It's a description of one particular type of component: the ideal linear resistor.

It doesn't matter how your power supplies are arranged in your circuit. Ohm's law has nothing to do with power supplies.

The general laws you want to consider that describe how currents and voltages relate in any circuit are Kirchoff's Current Law and Kirchoff's Voltage Laws. These laws, along with specific current-voltage relationships for each type of device (one of which is Ohm's Law), are the main tools for analyzing circuits.