# Solving Circuit Diagrams: 2 Batteries, Resistor & Subtraction

• majormaaz
In summary, to determine the total resistance in a circuit with 2 batteries and a resistor, you can use Ohm's Law to calculate the total voltage and current, and then use Kirchhoff's Laws to solve for the total resistance. If there are multiple resistors, you can use the equation Rtotal = R1 + R2 + ... + Rn to calculate the total resistance. If the batteries have different voltages, you will need to take into account the direction of current flow in your calculations. It is recommended to solve the circuit diagram in a systematic way, starting with identifying the voltage sources and resistors, and using Kirchhoff's Laws and Ohm's Law to calculate the total resistance and current. Redrawing
majormaaz
Just doing a couple circuit diagrams, and my brain seems to have shorted: If you have two batteries, but they're oriented where their negative terminals are facing each other (+ -) (- +) and there's a resistor in between the two batteries, could I still resolve the two batteries by subtracting the smaller battery from the larger one?

Sure, as long as you don't forget the resistor in the circuit afterwards. The position of a resistor does not matter in a series of circuit elements.

1 person

## 1. How do I determine the total resistance in a circuit with 2 batteries and a resistor?

In order to determine the total resistance in this type of circuit, you will need to use Ohm's Law, which states that resistance (R) is equal to voltage (V) divided by current (I). First, calculate the total voltage by adding the voltage of the two batteries together. Then, calculate the current by dividing the total voltage by the resistance of the resistor. Finally, use Ohm's Law to solve for the total resistance by dividing the total voltage by the current.

## 2. Can I use Kirchhoff's Laws to solve this type of circuit diagram?

Yes, Kirchhoff's Laws can be applied to this type of circuit. Kirchhoff's Current Law states that the total current entering a junction in a circuit must equal the total current leaving the junction. Kirchhoff's Voltage Law states that the sum of all voltage drops in a closed loop must equal the sum of all voltage sources in that loop.

## 3. How do I handle a circuit with multiple resistors?

If there are multiple resistors in the circuit, you can use the equation Rtotal = R1 + R2 + ... + Rn to calculate the total resistance. Just add up the resistance values of all the resistors in the circuit to get the total resistance.

## 4. What happens if the batteries have different voltages?

If the batteries have different voltages, you will need to take into account the direction of current flow in your calculations. The voltage drop across each resistor will be different depending on the direction of current flow. You can use Kirchhoff's Voltage Law to determine the voltage drops across each resistor and then use Ohm's Law to calculate the total resistance.

## 5. Is there a specific order in which I should solve the circuit diagram?

It is generally recommended to solve the circuit diagram in a systematic way. Start by identifying the voltage sources and resistors in the circuit. Then, use Kirchhoff's Laws and Ohm's Law to calculate the total resistance and current in the circuit. Finally, use these values to determine the voltage drops across each resistor and the direction of current flow. It may also be helpful to redraw the circuit diagram in a simplified form to make it easier to visualize and solve.

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