A closed path created by the connecting wires through a battery along which electrons can flow is called a circuit. For a continuous flow of electrons in the circuit it must be a complete circuit with no gaps left in between. Usually a gap is provided in the circuit by an electric switch that can be opened or closed to either cut off or allow current flow through the circuit. Circuits may have more than one device (called as component) that receives electric energy from the source. These devices are commonly connected in the circuit either in series or in parallel.
When the components of the circuit are connected in series, there will be a single path for flow of electrons between the terminals of the battery, generator or wall socket (which is simply and extension of these terminals). When these components are connected in parallel, they form branches and each branch provides a separate path for the flow of electrons.
Both the series and parallel connections have their own distinctive characteristics. We shall briefly study circuits, using these two types of connections.
Series connection of resistors| Activity 6 |
Take different bulbs. Measure their resistances with a multi meter. Note their values in your book as R1, R2, R3.
Connect them as shown in figure 16.
fig-16
Measure the potential difference between terminals of the battery connected to the circuit. V1 V2 V3 Measure the potential differences between the ends of each bulb and note them as V1 , V2 and V3 from voltmeters in your note book. Compare the potential difference of the battery and I A resistors.
The sum of the potential differences of the bulbs is equal to potential difference across the combination of the resistors. Then we get, V = V1 + V2 + V3 ........................(1)