ENGR 101
Introduction to Electrical Engineering
Session 2
1. Use an ohmmeter to measure the resistance of 4 randomly selected resistors. Record the color code
and determine the resistance value from the color code.
Resistor #
Colors
Value from
Value from
Color Code
Measurement
1
2
3
4
2. Measure the values of 470 and 1000 resistors. Construct the circuit shown below on the
breadboard. Use the DC power supply as the voltage source. Measure and record the voltages VAB,
VBC, and VAC.
A
B
R1 =
470
VSS =
12 V
R2 =
1000
C
R1 = _____________
VAB = ____________
R2 = _____________
VBC = ____________
VAC = ____________
Use Ohm's law to calculate the current through R1 and R2. (IR1 = VAB / R1)
IR1 = _____________
IR2 = _____________
You should have found that IR1 and IR2 have the same current. Divide the supply voltage (12 V) by
the circuit current to obtain an equivalent resistance.
REQ = _____________
How is REQ related to R1 and R2? What is the mathematical expression?
REQ = _____________