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Worked example of a series-parallel combination circuit.

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Firstly name the resistors.

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In this exercise resistors 1 and 4 are in series and resistors 2 and 4 in parallel.

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We have to calculate first the equivalent resistance.

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The total equivalent resistance of the circuit.

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Calculate the equivalent resistance between resistors 2 and 3.

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This gives us 12 ohms.

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By calculating the equivalent resistance to R2 and R3, we can simplify the circuit to a series circuit with R1, R4, and R2-3.

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Finally adding this three resistors you get 22 ohms.

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The total current flowing through the circuit.

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We use Ohm's law to calculate the total current, because we know the equivalent resistance and the voltage delivered by the cell.

12
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so that total intensity is 5 volts between 22 ohms giving 0.23 amperes the voltage or potential

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difference across each resistor the correct order to do this part is calculating first the drop of

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voltage in the resistors 1 and 4 in series we know that the intensity that flows through them

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is 0.23 amperes. So applying Ohm's law in each of them will give us the voltage in these resistors.

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For the resistors that are in parallel, we know they share the same voltage as they are in parallel.

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You can calculate this voltage with the Ohm's law, voltage equal to 0.23 amperes by 12 Ohms,

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or with the difference of the voltage of the cell, that gives you the same result.

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The currents I1 and I4 are equal to the total current of the circuit 0.23 amperes.

20
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We use Ohm's law to calculate I2 and I3.

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You can check that the addition of these two intensities is equal to the total intensity.