Circuits WS & Lab

I won't make you turn this in this year (I want you to concentrate on your project proposals) but you should know how to do this (it might show up on the midterm). 

Just stick with measuring R and V for now, calculate the current (this way we don't have to worry about blowing fuses).

 

Circuits Lab

The purpose of this lab is to theoretically estimate and empirically measure current and voltage for a series circuit and a parallel circuit.  Your group has the following materials to complete the lab: breadboard, resistors, 9V battery and leads, multimeter, and jumper wires.

Lab Procedure

1.       Begin by measuring the voltage of your 9V battery.  Place the red lead on the “+” side of the battery and the black lead on the “–“ side of the battery and note the measurement as V_DC.

2.       Identify the resistance values of the resistors you’ve been given by using the Resistor tables.  On your lab, note the value of the resistor you used for R₁, R₂, and R₃. 

3.       Measure the voltage drop across each resistor.  V₁ corresponds to the voltage drop across R₁, and so on.  Record the voltages for both the series and parallel circuits as the experimental values.

4.       Calculate the current.  In the series circuit, you will only have to calculate I.  In the parallel circuit, you will need to calculate I₁, I₂, and I₃.  Record the currents for both the series and parallel circuits as the experimental values.

5.       Using the values you obtained for V_DC, R₁, R₂, and R₃, calculate the theoretical values for the voltages.

6.      
Calculate the percent error for the voltages and currents.  Percent error is calculated as:

Where theoretical are values using V = 9V, and ideal resistor values, and experimental are using actual voltage and resistor values you measure with your multimeter.

Resistor Color Codes – Brown resistors

1^st and 2^nd color bands (representing first two digits of resistance)

Black = 0                 Orange = 3              Blue = 6                   Gray = 8

Brown = 1               Yellow = 4               Violet = 7                                White = 9

Red = 2                    Green = 5

3^rd color band (multiplier)

Black x 1                  Orange x 1k                             Blue x 1 meg          

Brown x 10              Yellow x 10k                            Silver ÷ 100

Red x 100                                Green x 100k                           Gold ÷ 10

4^th color band (tolerance)

Gold = 5%                               Silver = 10%                            None = 20%           

Blue (precision) Resistor: 1^st 3 bands = 1^st three num’s of R, 4^th band is multiplier, 5^th is tolerance.
#1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:

#2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Bring up excel, and create some spreadsheets with the tables shown below. 

#3~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Make sure you understand how to add resistors in parallel and in series for the test.


If you finish, play around making some of the other ciruits from the electronics kit!  Google what you are making to see how it works!