Circuit problem

1.  Consider a circuit with 4 resistors, connected to a battery (12 V):  1 and 3 ohms in series, connected (also in series) to a pair of resistors (6 and 12 ohms) which are in parallel with each other.

Find all currents and voltages in the circuit.  Hint - find the total resistance first.  Recall that resistors in series add to get a total resistance. In parallel, you need to add the inverse of the resistors, and take the inverse of that quantity.

2.  Knowing that power (P) is work over time (W/t), derive a simple expression for electrical power (which will have measurable quantities such as V, I and/or R in it).