Question

What do you understand by the term series circuit?

Answer 1

Series circuit: When a number of resistances are connected in an electrical circuit in such a way that positive of one resistance acts as the negative of the other resistance, then resistances are said to be in series.
OR
A number of resistors are said to be in series if these are joined end to end and the same current flows through each one of them when a potential difference is applied across the combination.

Here, the three resistors R₁, R_2, and R₃ are in series.