Resistors in Series and Parallels, not feelin' creative today

Objectives:

- To study current flow in series and parallels

- To study voltages in series and parallels

- Use Ohm's law to calculate equivalent resistance of series and parallels

Key Terms:

- voltage

- circuit

- electricity

- series

- parallels

Pre-Lab Discussion :

What do Series Resistors look like? What do Parallel Resistors look like? What is the difference between the two?

Resistors in series come in succession of each other. In parallel resistors, the resistors split on their owns paths and provide separate "roads"

What is Ohm's Law? 

Ohm's Law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the following mathematical equation can be used to describe the relationship:

Our Setup ft. The Physics Students:

Procedure and Data:

Resistor One: 1.08V/0.055A = 19.6, close to the actual resistance of 20 (Two 10 Ohm resistors)
Resistor Two: 1.12V/0.018A = 62.2, close to the actual resistance of 61 (Two Resistors: 51 and 10)
Resistor Three: 1.05V/0.0104A = 100.96, close to the actual resistance of 102 (Two 51 Ohm resistors)

Resistors 51 and 51: 1/51 + 1/51 = 2/51 or 51/2 * 0.0404 = 1.03 V, or the voltage recorded

Resistors 51 and 68: 1/51 + 1/68 = 68/3468 + 51/368 = 119/3468 or 3468/119 * 0.035 = 1.02 V, or about the voltage recorded

Resistors 68 and 68: 1/68 + 1/68 or 68/2 = 34 * 0.031 = 1.054 V, or about the voltage recorded

In the following section, we compared a parallel circuit with 10 and 51 Ohm Resistors as well as 51 and 68 Ohm Resistors. In this experiment, we expected the experiment to begin, and with a different current going through each resistor. 

The ratio of the currents (A1/A2) should equal (R1/R2)
In this photo, we can see a different current going through each resistor, proving that the current will split between the two resistors.  The split is clearly not equal. 

      In this photo, we also see the current splitting between the 10 and 51 Ohm resistors. The split is clearly not equal. 

Analysis:

1. Describe Resistors in Series and Parallel 

In Series circuits, there is only one pathway for the flow of electrons. The current running through each resistor is equal, and the net change of energy is 0. The more resistors in a series, the lower the overall current of the system. In order for series to work, all resistors must be functioning. 

In Parallel circuits, the current has multiple pathways available to cross. The current running through is split to the resistors, and not necessarily evenly. As the number of resistors increases, the overall current increases. Unlike series, parallel circuits are able to function with one resistor gone, but not as efficiently as before.  

2. Describe the flow of the current in resistors in series? 

We proved that the flow of current in resistors in series is equal. 

3. Describe the flow of the current in resistors in parallel? 

We proved that the flow current in resistors is split between the pathways and the different flows of current are not necessarily equal.

4. Which resistor had the larger current flowing through it? 

In our experiment with the two set of parallel resistors, we found that the resistor with the highest value of resistance had the highest value of current flowing through it. We assume this is due to a higher resistance, or a higher tolerance for the current. Otherwise, the resistor overflows and overheats and starts to smoke as you yell "MAXIMUM VOLTAGE" and your teacher looks on with disapproval wondering how his brilliant physics students managed to destroy a 10 Ohm resistor with only 3 volts.