1. To find the value of a resistor and its tolerance by color coding. 2. To measure the value of the resistor by Digital Multi-meter (DMM). 3. To verify Ohms la! e"#erimentally and to find the relationshi# bet!een b et!een voltage$ current$ and resistance in a circuit. II! E$%I&MET:
D% &o!er su##ly Ten Ten (1') ssorted %arbon %om#osition *esistors bet!een 1 + to 1 M + Digital Multimeter !ith test leads %onnecting !ires
III! &ROCE(%RES: &ART ): I(ETI*ICATIO O* RESISTOR COLOR CO(ES
1. ,elect five five resistors resistors to to use in this lab lab activity. activity. se the #rovided #rovided table table to record data$ data$ calculations$ and observations. se #encil only. ave your teacher chec/ your #rogress at chec/#oints 01 and 02. and in this sheet for evaluation !hen it is com#leted. 2. oo/ at each resistor resistor and and identify identify the 3 bands used to to calculate calculate resistance. resistance. ist ist the colors in the table under resistance colors. oo/ at the fourth band and decide !hether it is a (4old)$ 1' (,ilver)$ or 2' (no fourth band color) tolerance resistor. &lace the resistor tolerance in the table under tolerance. tolerance. 3. se the chart chart to calculate calculate the the resistance resistance of of each resistor resistor according according to the colors colors you have have listed. &lace the resistance calculations in the table un der calculated resistance resistance.. 5e sure to label all resistance values !ith the ohms symbol (Ω). 6. %onvert %onvert the calculated calculated resist resistance ance of each each resistor resistor to 7ilo-ohm 7ilo-ohmss or Mega-ohms$ Mega-ohms$ as as necessary$ and #lace in the table under converted calculation. calculation. 8f no conversion is necessary$ co#y the calculated resistance into the converted resistance s#ace. resistance s#ace. 5e sure to label all resistance values as Ω$ 7 Ω$ or MΩ. 9 ,TO& for teacher chec/ and teacher demonstration.9 . Meter the the resistance resistance of of each resistor resistor.. &lace &lace the readings readings in the the table under under metered resistance. resistance . 5e sure to label all resistance values as Ω$ 7 Ω$ or MΩ. AES +,) - BASIC ELECTRICAL E.IEERI. E.IEERI. by: Enr! Ma! /ristina &! Bor0on1 MEECE
&age 1 of 6
;. %alculate %alculate the accuracy accuracy of each each resistor resistor using using the the formula formula on the bac/ of this this sheet. sheet. &lace &lace your calculations in the table under accuracy. accuracy.
<. 8n the the tab table le unde under r rating $ state !hether you !ould rate each ea ch resistor as good or bad.
Resistor La0 (ata Ta0le Ta0le *esistor =umber
*esistance %olors 5and 1 5and 2
5and 3
%alculated *esistance
%onverted *esistance
Metered *esistance
Tolerance
ccuracy
*ating
1 2 3 6 ; < > ? 1' ,to#@ 4et your !or/ %hec/ed.
,to#@ 4et your !or/ %hec/ed.
$estions:
1. Ahat is the value of resistor having colors red$ red$ yello! and goldB
1. ssemble on the bread-board the circuit sho!n in Eigure 2.; using the same voltage setting on the #o!er su##ly and the same resistor as sho!n. 2. ,et the multi-meter to measure dc current$ ma/e sure that the leads are correctly set for current measurement. 3. Measure the current flo!ing through the resistor. resistor. Does this value agree !ith the calculations
i = v R using OhmFs a! B 6. Measure the current flo!ing through the resistor in the o##osite direction. This is done by reversing the leads of the ammeter. Does this value agree !ith the calculations using OhmFs a!
i = v R B
. %om#lete the follo!ing table. Dra! a gra#h bet!een the measured voltage and current for each value of resistanceG and find out the a##ro"imate value of resistance through the gra#hs dra!n. AES +,) - BASIC ELECTRICAL E.IEERI. E.IEERI. by: Enr! Ma! /ristina &! Bor0on1 MEECE
