In order to demonstrate the use of a resistor, we built a circuit, which included a power source, resistor, and light bulb. As the name implies, a resistor adds resistance to a circuit, reducing the amount of current flowing through the circuit. Therefore, we predicted that the light bulb would not shine as bright as it would have without the resistor because there would be less power in the circuit. Our predictions were right. When we added more resistors to the circuit, the light bulb became dimmer as the amount of resistor present in the circuit increased. This was also true when we replaced the light bulb with a buzzer. Without a resistor, the buzzer sounded off with a relatively high volume. As we added more resistors, the volume of the buzzer decreased. In both cases, overall power decrease was the reason for a dimmer light or softer sound.

Power use is also important in any type of circuit. To demonstrate this, we built a series circuit with different amounts of blinking light bulbs. Each one of the bulbs contributes to the overall resistance of the circuit because each light bulb will use power in order to light up. The more light bulbs are present, the more power is needed. The circuit with all three light bulbs connected produced a rather dim light in all bulbs. This is due to the relatively high power requirement. As the number of light bulbs in the circuit decreased, the light brightness increased.

Each of our circuits displays basic, yet important information about circuits. In the first circuit, we were able to display the importance of fuses in circuits. We concluded that fuses are needed in order to prevent serious damage to circuits. For example, the burning of the wires which could start a fire. In the next circuit we built, we showed the convenience of a switch. While another element of the circuit was operating, we could control at anytime when another element could be turned on and off. Our last circuits demonstrated the importance of resistors and how it affects power usage. More resistors means less current. This, in turn, means less power in the total system.