Resistors in parallel share the same voltage drop. So we take the voltage drop, V =
4 V, back to diagram. The voltage drop across each of the two parallel resistors
in diagram is 4 V.
Since we know the voltage drop across each resistor, we can figure out the current
through each resistor by using the equation. The current through the 3 Ω
resistor is , and the current through the 6 Ω resistor is.
Notice that the current entering the parallel combination (2 A) equals the total
current passing through the individual resistors ( A + A).
Finally, we will calculate the power dissipated as heat by each resistor. We can use
any of the equivalent formulas: P = IV, P = I^2 R, or P = V^2 /R.