Lab
2: Resistive Circuit
Objective:
To study simple resistive circuits, to verify Ohm.s law and practice using a multimeter.
Apparatus:
Three resistors; R_{1}=324W R_{2} =
83W R_{3} = 268W , two multimeters, test
leads, power supply, breadboard.
Instruction for Breadboard:
Note that the holes on each column of the breadboard as marked in the picture below are physically connected inside. By examining the pictures, study how the connections are made for a given circuit. Ask your instructor if you have any problem understanding the usage of the breadboard. It is helpful to use one color, for example red for positive terminal, and black for ground or negative. During any time you can refer to color coding to follow the connection. Set up the circuits sketched below on a breadboard.
FIGURE 1:
The picture above depicts two resistors in series and connected to a power supply V.
On the left is the physical appearance on the breadboard, on the right is the symbolic representation used on paper.
FIGURE 2:
The picture above depicts two resistors in parallel and connected to a power supply V.
On the left is the physical appearance on the breadboard, on the right is the symbolic representation used on paper.
FIGURE 3:
This figure shows a wrong connection where resistor and power supply are shorted out. Can you see why?
Procedure:
Measure resistance for each of the resistors and record. You will be using these values in your calculations. Each table below will have an entry for calculation and measurements. Your goal is to compare the two.
First we will establish the relationship between the voltage applied and the current in a simple circuit in part A below. Then we will set up various circuits.
R_{1}: _____________R_{2}: ___________R_{3}: ______________
A: Ohm’s Law:
Set up the circuit shown and change the voltage between 0
and 5 volts five times. Record the corresponding currents.
Produce a graph of V versus I. Use R_{1}.
V(Volt) 
I(mA) 










B: Series Circuit:
Set up the three resistors as series. Calculate the current in each and voltage across each resistor and record. Enter the values of your three resistors in the first column.
Measurement 


Calculation 


R(W) 
I(mA) 
V(Volt) 
R(W) 
I(mA) 
V(Volt) 


















C: Parallel/Series Combination:
Set up the three resistors as shown. Calculate the current in each and voltage across each resistor and record. Enter the values of your three resistors in the first column.
Measurement 


Calculation 


R(W) 
I(mA) 
V(Volt) 
R(W) 
I(mA) 
V(Volt) 

















