1. In a circuit or any part of a series circuit, current flows only in one direction.
2. The voltage drop across each resistance in the circuit, combined together, is equal to the voltage applied to the circuit.
3. Value of each sub-resistance in the circuit When they are combined, they are equal to the total resistance of the circuit.
4. Power and electrical energy arising at each of the sub resistances in the circuit. Taken together, they are equal to the total power and energy in the circuit.