Resistance in Series

Resistors can be connected in two ways in a circuit. The connections are:

1. Connection of resistors in series.
2. Connection of resistors in parallel.

Resistance in Series:

When three resistors, R₁, R₂ and R₃ are connected in series, i.e. one end to another end to form a linear network, the same amount of current flows through them when they are connected to a source of e.m.f.

The total resistance, R (or effective resistance) is given by V = IR_eff

From the circuit diagram, the voltage V is connected across the three resistors. This voltage is shared across each of the resistors.

Remember that the voltages drop across each of the resistors are different because the resistances of the resistors are different. Therefore, let the voltage of the cell, connected across the three resistors, be V.

Let the voltage drop across resistor R₁ be V₁.

Let the voltage drop across resistor R₂ be V₂, also,

Let the voltage drop across resistor R₃ be V₃.

Therefore the total voltage can then be found;