As a test if we enter resistances of 4 6 and 12 ohms the. Then once you have this value you then need to do an in series calculation using the resistor on its own and the result of the first calculation you did to give the total resistance for the circuit. Resistors In Series And Parallel Formula Derivation Resistors Parallel Formula Parallel Circuit Splitted into Multiple Series Circuits. . The standard formula for calculating the total resistance for a number of resistors in parallel is given. A parallel plate capacitor kept in the air has an area of 050m 2 and is separated from each other by a distance of 004m. In this way we can infer the voltage across resistors R3 will be the same of the total voltage of the circuit. The only resistors available to you are two 1 kΩ resistors one 500 Ω resistor and a rheostat variable between 600 and 1000 ohms. Calculate the current I in this circuit if the resistors are both ohmic in