If an electric motor is the load in our circuit, it is the means of converting electrical energy into mechanical energy which is motion. If a toaster is the load, electrical energy is converted into heat. And the same is true if the load is an electric stove.
From this simple, fundamental circuit all sorts of complicated circuits arise. Look at a diagram of a Radio circuit, it may seem extremely complicated. But there is this cheering thought, that no matter how complex a circuit may be, it can always be divided up into fundamental circuits--and there will always be a source of e.m.f., conducting wires, and one or more loads in each.
We shall go on to consider slightly more complex circuits, building up our knowledge gradually , so that by the time you finish this lesson, even the diagram of a complex modern
Fig. 1
Fig. 2
superheterodyne “circuit” will mean much more to you than a maze of lines and symbols.
As you learned in the last lesson, several dry cells may be connected either in series or in parallel to form the source of e.m.f. In the same way, the load in the circuit may consist of several parts, or as we more commonly say, there may be several loads in the circuit. These loads may be connected either in series or in parallel in the same manner as several dry cells would be connected together. But no matter how many parts there are to the source, or how many parts the load has, the thing to remember is that they must all be connected together so that there can be a continuous path for the current through each dry cell and through each load.
Very naturally, when we add a second load to a circuit, the electrical energy in that circuit is going to be divided between
