In a series circuit, the total resistance is the sum of the individual resistances connected in a series, and it is calculated using the following formula:
Total Resistance (R_total) = R1 + R2 + R3 + ... + Rn
Where:
R_total is the total resistance of the series circuit.
R1, R2, R3, ..., Rn are the individual resistances in the circuit, where "n" is the total number of resistors connected in series.
In simpler terms, if you have two resistors with values R1 and R2 connected in series, the total resistance (R_total) is the sum of R1 and R2:
R_total = R1 + R2
For example, if you have resistors of 10 ohms and 20 ohms connected in series, the total resistance would be:
R_total = 10 ohms + 20 ohms = 30 ohms
Keep in mind that in a series circuit, the current (I) remains the same through all the resistors, and the voltage across each resistor adds up to the total voltage applied to the circuit. This is governed by Ohm's Law:
V_total = I * R_total
Where:
V_total is the total voltage across the series circuit.
I is the current flowing through the series circuit.
R_total is the total resistance of the series circuit.
By knowing any two of the variables (V_total, I, or R_total), you can calculate the third using Ohm's Law.