They were explaining how electrical circuits work can be quite a task. Of course, we can probably not see these tiny electrons – considering their 0.00282 pico-meter sizes. But let’s imagine the three essential components of an electrical circuit: current, voltage and resistance. Let’s say current represents an army of soldiers, voltage represents the energy level of each soldier, and resistance represents a high wall all the soldiers are expected to climb over to complete the course.
The current in the diagram above is illustrated by a small ‘e.’ Each ‘e’ or soldier has its energy maxed in its barrack, representing the energy bank from which the soldiers source their energy. This energy bank is called the voltage source. After the current leaves the voltage source, it would follow the pathway (of course) that has been created for it – the pathway in electrical terms is constructed using wires. It represents a series circuit with one single loop or parallel circuit.
All the soldiers in a series pathway will travel the same route (of course, because there is no other route!). The soldiers will determine how they will use all of the energy they had received from the barrack before returning. In a complete course (or circuit), there have to be some obstacles or high walls that the soldiers have to jump over. They (the soldiers) will allocate portions of their energy to each partition depending on how high the wall or resistance is. Upon returning to their barracks, all the soldiers would have completely zeroed their energy level so that they could refill to maximum their energies once again.
All the soldiers in a parallel pathway will travel the same route until they reach a junction (or split in the path). This junction in electrical terms is called a node. At the node, the soldiers will compare the resistance of each course, and most will take the path that poses the least resistance – only a few will take the path of high resistance. Still, all soldiers will eventually use the same energy once they reunite at another junction later down the pathway. Upon returning to their barracks all the soldiers would have completely zeroed their energy level so that they are able to refill to maximum their energies once again.
We use three devices to measure each of the three essential components of an electrical circuit. These are: ammeter for current, voltmeter for voltage and ohmmeter for resistance. We place the voltmeter and ohmmeter across the course section we want to measure. First, however, we place the ammeter inside the circuit at the point we want to measure.
Ohms Law and Kirchhoff’s Current and Voltage Laws govern the properties of electrical circuit behaviour. Ohms Law states the Voltage = Current x Resistance. Kirchhoff’s Current Law states that all currents entering a node (remember, a node is a junction in the pathway) are equal to all the current leaving the node. Kirchhoff’s Voltage Law states that the sum of voltage drop across resistors in series is similar to the source voltage. The following post will elaborate on these laws.