A serial circuit is a circuit in which the elements are connected in such way that the current can have only one route to take.

Two or more lamps (resistances R₁ and R₂, etc.) are connected in a circuit as follows (Figure 10), there is only one route that the current can take. The value of current I is always the same at any point in a series circuit.

The electrical circuit equivalent to the one shown in figure 10a is presented in figure 10b. There is also presented the way that the current is passing through the circuit and which is the equivalent resistance.

 

Serial circuit

a. practical view; b. electrical view

The switch has the role to provide current to the circuit so that the other components can function properly. And the power supply has the principal role to generate energy for the circuit.

The combined resistance R₀ in this circuit is equal to the sum of individual resistance R₁ and R₂. In other words: The total resistance (R₀) is equal to the sum of all resistances (R₁ + R₂ + R₃ + .......)

 

 

Therefore, the strength of current (I) flowing in the circuit can be found as follows: