Case: Read the following passage and answer accordingly.

The current through a single resistor R across which there is a potential difference V is given by Ohm's law I = V/R. Resistors are sometimes joined together and there are simple rules for the calculation of equivalent resistance of such a combination. Two resistors are said to be in series if only one of their endpoints is joined. Two or more resistors are said to be in parallel if one end of all the resistors is joined together and similarly the other ends joined together.

A current of 18A divides between two branches in parallel of resistance 8Ω  and 12Ω respectively. What is the current in each branch?

18.4A, 10.8A

Since the resistors are in parellel combination, 1/R_eff = 1/R₁+1/R₂

                                                                             = 1/8+1/12 = 5/24

                                                                       R_eff = 24/5=4.8Ω

                                          Voltage across resistors = IR_eff = 18x4.8 = 86.4V

                                                  current across 8Ω = V/R = 86.4/8 = 10.8A

                                                current across 12Ω = V/R = 86.4/12 = 7.2A