Dc Circuits & Ohms Law

Elizabeth Rodriguez

P132 Lab LQ

October 6, 2015

DC Circuits and Ohm’s Law

Introduction

The purpose of this lab is to look at the concepts of Direct Current in electrical circuits by taking measurements of the voltages and currents in these circuits. From this experiment we will be able to determine whether or not our carbon resistors are Ohmic devices and show how voltage and current are related to each other based on the type of resistors.

Questions

1.) The equation for Ohm’s Law is R=V/I. Voltage is known as the amount of energy supplied per charge and the units of V is one Volt also known as Joules/Coulomb. I is known as the amount of charger in motion per second and is called the current. The units of the current are in Amps also known as Coulombs per seconds. The R in this experiment is the resistor.

2.) From the graph we can see that the data points fall on a fairly straight line aside from one point where our measurements must have been off, however it is clear that it follows the trend line and does not curve. To determine if the current changes, we can use ohms law to see if there is a difference between points. In the case of this part of the experiment, we were not measuring the current however whenever a voltage is applied across a resistor, a current flows through the resistor. Because the voltage increases the more we change the position x, we can see that the current is changing as we change x.

3.) Using the data obtained from the experiment we were able to calculate the slope in excel. Our value of R from the color coding on the side of the resistor was found to be 47 and when we measured it with the ohmmeter we got a value of 46. From the graph our slope value was equal to 50 which is pretty close to the values we got from the color coding and ohmmeter.

4.)

Resistors in Series and Parallel | | | | |

|   | | R2 (color code) = | 47 | |

R1 (color code) = | 47 | | R2 (ohmmeter) = | 48.34 | |

R1...