SUMMARY
Resistors control the flow of the electric current in a circuit.
Two or more resistors are said to be connected in series when the same amount of current flows through all the resistors.
The total resistance of a series circuit:
R total = R 1 + R 2 + ... + R n
Two or more resistors are said to be connected in parallel when the voltage is the same across all the resistors.
The total effective resistance of a parallel circuit:
