individual circuits

We first learnt about voltage, resistance, current and power. Voltage, V, is measured in volts, v, and is the energy or pressure behind the current. Resistance, R, is measured in ohms, Ω and is what makes it harder for the current to flow around a circuit. Current, I, is measured in amps, A, and is the amount of electricity flowing around the circuit. Power, P, is measured in watts, w, and is the power output of a component or circuit. The first part of the electrical unit was individual circuits. These are simple cirrcuits consisting of a DC power supply, fuse, switch and a lightbulb, and then the circuit was earthed back to the power supply.

We then began to carry out tests. The first test was the available voltge - which is the voltage available at any given point on the circuit. We tested the avaible voltage at the positive of the 12V DC power supply, at the terminals before and after the switch, at the terminals before and after the light bulb and at the negative of the power supply. Getting accurate measurements became difficult because of the fluxuating voltage of the power supplu. In doing this I found that the only major voltage drop was at the light bulb. There were minimal voltage drops at the switch and wires which is explainable by a small amount of resistance in these components. We then measured the current flowing through the circuit by connecting the ammeter in series before the light bulb. This turned out to be .36 amps. We then used Ohms laws to calculate the resistance and power of the light bulb. We then did the same circuit with a bigger bulb and found that there was a higher current draw, less resistance and a higher power out put in the circuit with the bigger bulb.