Technical data

20
hm’s Law
elationship of I and R with a Constant V
roject Objectives:
• To prove the inverse relationship of current to resistance when a set voltage is given.
• To obtain practice in connecting circuits and using a DMM to make measurements.
ems Needed:
- Electronics Trainer - Digital multi-meter
- Jumper Wires - Resistors 10k, 3.3k
• Be sure to disconnect power when connecting
the circuit!
• When measuring current, make sure a resistance is al
shorting the circuit and damaging the meter.
O
R
P
It
, 1k
meters and making component changes to
ways in the circuit to avoid
Experiment
1. l
2.
3.
4.
Voltage measures = ____________________ V
5. Use Ohm’s Law and calculate the resistance (R) from the measured values of voltage (V) and
current (I).
Calculated Resistance = ____________________ 
6. What would the current of the circuit be if the 10k resistor were replaced with a 3.3k (orange,
= ____________________ mA
Se ect the correct meter range to measure dc current from
0 – 2mA.
ng the positive variable voltage as the source Usi V,
connect the circuit shown in figures 5-1 and 5-2.
the meter is in series with the circuit.
Turn on the power supply and increase the positive
variable voltage until the meter reads 1mA.
Measure the circuit voltage and be sure not to change it
for the rest of the steps in this experiment.
Make sure
orange, red, gold) resistor?
New calculated current
+
−
mA
10
k
Ω
Source V
Figure 5-2 Schematic Diagram
0.00
A
m
A
COM
V
Ω
+
−
Variable
0 to +20vd c
Variable
0 to -20vdc
voltage
Variable
output
10
k
Ω
terminal
mA
Figure 5-1 Pictorial Diagram