|Here is an alternate way of solving the example problem.
Instead of first finding all the resistances, we can begin the problem
by finding the emf voltage first.
By Ohm's Law, we know that the emf is equal to the product of the total current and the total resistance.
= (1.0)(30) = 30 V
Figure 1 Example Problem, with given data
Also, the total voltage, V, is equal to the sum of the voltages across the resistors in this circuit (because this is a series circuit).