Neupane_Suyog_Lab_RColorBands

docx

School

University of Texas, Arlington *

*We aren’t endorsed by this school

Course

1106

Subject

Electrical Engineering

Date

Apr 3, 2024

Type

docx

Pages

Uploaded by CountFlagGoose33

EE1106 Lab: Resistor Color Codes PreLab Instructions: Take good notes in your lab notebook while watching the lecture video and reading the articles . Answer questions in your lab notebook. After the questions, re- create the data tables in your lab notebook and be ready to record measurements and calculations during the lab time. Watch Lecture video on Canvas Read: Sparkfun article on Breadboards Read: Sparkfun article on Multimeters Read: Color Band article on arrow.com (feel free to google other color band charts) Read Online Circuits Text Volume I – DC Current and take notes in your lab notebook as you read . Create a study guide for the concepts in your lab notebook  Chapter 1 – Basic Concepts of Electricity  Chapter 2 – Ohm’s Law  Chapter 5 – Series and Parallel Circuits In your lab notebook, answer the following questions: 1) How does the resistance of a circuit element depend on its material and geometry? 2) What is a multimeter? Draw basic diagrams for measuring voltage across and current through a resistor using a multimeter. 3) What is the relationship between voltage and current for a resistor? 4) A five band resistor has all yellow colored strips. Show your work to calculate its value.

In Class assignment: Lab Goals:  Understand the structure and usage of the Breadboard.  Understand and appreciate the resistor color band chart  Understand usage of a Digital Multimeter (DMM) for measuring resistance and continuity  Use the DMM to measure several resistor values. Lab Material: • Breadboard, wire cutters, wire stripper o You will be able to borrow these materials for this lab Due at the beginning of lab next week: • Lab report Part1: Digital Multimeter  If not using your own meter, obtain multimeter probes from the wall in the lab and connect them to the proper location on the front of the meter for taking resistance and continuity measurements.  Configure the multimeter to read continuity and verify the functionality by shorting the tip of the probes together  Place jumper wires in the breadboard in ways that allow you to investigate the various ways of creating (or preventing) continuity in a circuit  Configure the multimeter to measure resistance. Grab the end of each probe (one in each hand) and take a measurement of your bodies resistance Part2: Resistance Measurements Resistors are the most common electronic component found in circuits and systems. This lab experiment is designed to: • Sharpen your skill at reading specified values and tolerances from resistor color bands, and • Introduce you into taking resistor measurements using the DMM. Experiment Procedure The lab will provide 5 numbered plastic bags containing axial-lead (through-hole) metal film resistors of various values and tolerances. These are commonly used to build circuits on a breadboard. Your task is to complete the entries in Table 1 using the resistor color guide. The procedure for this job is as follows:  The body of each resistor has at least four colored bands around it. Using only the resistor color guide, fill out Table 1 for each resistor’s specified value and tolerance. Do not spend a lot of time. Make your best guess on the colors and positions of each band. Calculate resistor values for all five resistors BEFORE moving to the next step

 Install the resistors on your breadboard (across the gap is best). The resistors should be secured so that good measurements can be taken. The lead on each resistor needs to be trimmed such that the body of the resistor is in contact with the surface of the breadboard and the leads are going down far enough in the breadboard to make good contact below the surface of the breadboard. Experiment with how far the untrimmed resistor lead goes down into the breadboard before trimming the leads.  Configure the DMM to measure resistance and measure the actual resistance of each resistor; record these values in the measured value column of the Table. Make sure you carry out several measurements (discuss in your report how many measurements, how you carried out your probing, etc) .  Take note of errors from your color band calculations. Describe in your notebook how you may have misinterpreted a color or band position that caused the error. Compute the error in percent (%) between the corrected color band value and the average measured value for each corresponding resistor; record these in the error column; use the color band or specified value as the basis for the percent, that is Error (%)  Measured  ColorBand  100% ColorBand (1) For any percent error value that is out of tolerance, create a second table to document the errors . This table should have the correct color band values that represent the correctly measured resistance value. The first two rows in Table 1 illustrate an example of the procedure on two resistors R a and R b . Resistor R a in the first row has 4 color bands with colors green (5), brown (1), orange (3), and gold (±5%). The specified value of this resistor is determined from R a  5 1 000    51 k  (2) with a tolerance of ±5%. However, its value measured with the DMM is 50.5KΩ as is recorded in column 10. The error between its measured and specified values is computed from equation (1) where Error (%)  50.5 k   51 k   100%   0.98% 51 k  (3) The point of this lab is not to get you to read color bands 100% correct 100% of the time, but rather to appreciate the difficulty in having to calculate a resistor based on the color bands as opposed to using a proper piece of measurement equipment. There are engineers and technicians who have much experience with these devices and can glance at a resistor and know the value immediately. This knowledge is not expected from EE students. A first year EE student needs to appreciate the technique required to make a proper measurement so that there is no need to memorize color bands.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Record your body resistance from Part 1 Table 1 Color Band Color Band Value Color Band Tol % Meas Value Error % R # of Bands 1 2 3 4 5 R1 4 Brown Brown Yellow Gold - 110k +/- 5% 109.5k -0.45 R2 5 Brown Green Black Red Brown 15k +/-1% 14.98k -0.133 R3 5 Orange Black Black Red Brown 30k +/-1% 30.217k 0.7 R4 5 Green Brown Black Brown Brown 5.1k +/-1% 5.098k -0.19 R5 5 Red Blue Brown Brown Orange 2.61k +/- 5% 2.61k 0 R6 5 Grey Red Green Brown Orange 8.25k +/- 5% 8.227k -0.278 Assuming you take good measurements and trust the meter, correct the color bands for any resistor that was incorrectly calculated in the previous table. In your lab report, provide a narrative explanation for what went wrong in your calculation. I.e., a color was interpreted wrong, a band meaning was interpreted wrong, the bands were read in the wrong direction (right/left left/right), etc. Table 2 Corrected after Measurement if needed Color Band Color Band Value Color Band Tol % Meas Value Error % R # of Bands 1 2 3 4 5 Ra* 4 green brown orange gold N/A 51K ±5 50.5K -0.98 Rb* 5 red orange violet red brown 23.7K ±1 23.8K +0.42 R1 R2 R3 R4 R5