Series Curcuit:
Series circuits have only one path that the current follows. In series circuits, the total resistance is equal to the sum of the resistances of each resitor. Also, the current is the same througout the entire circuit. However, the voltage drop depends on how much resistance each resistor has. In this example, all the light bulbs have the same resistance, so the voltage drop across each is the same. The total voltage is equal to the voltage drop across each resistor. Ohm's law states the the current is equal to the voltage divided by the total resistance. In other words, the more resistance is added, the lesser the current is. The more voltage is added, the greater the current is. If one bulb was removed, the rest would go out. The filaments in the bulb connect the circuit. If one is removed, then the circuit is broken, so no current is drawn.
Parallel Circuit:
Parallel Circuits have multiple paths. To be purely a parallel circuit, all of the resistors have to be on their own path after the circuit splits into those paths. In parallel circuits, the total resitance is equal to the reciprocal of the sum of the reciprocals of each resistor's resistance. In this case, the more resistance is added, the lesser the total resistance is. The current in parallel circuits is equal to the sum, of the current in each path. Voltage drop is the same throughout all the resistors in the parallel circuits. The more voltage is added, the greater the circuit. The more resistance is added, the greater the current, also. If one bulb is removed, the others would still be on. The circuit would not be broken for the other bulbs.
Series and Parallel Combination Circuit:
Combination circuits have both series and parallel circuits. The total resistance is found from finding the total resistance of each section. In the example above, a parallel circuit is connected in series with another resistor. First, one should find the resistance of the parallel circuit, then add that to the resistor that is connected in series. The voltage drop in the series portions of combination circuits is added, but in the parallel portions it is the same. In the series portions, the current is the same, but in parallel portions, it is added. If one bulb was removed, everything that is connected in series would turn off. I in my diagram, if one of the bulbs in the parallel portion was turned off, then the others would still be on. If the bulb in the series was removed, then the other would turn off because the circuit to the parallel bulbs would be broken.
