Instruction manual

Basic Electricity 012-04367E
36
Exp 6- Currents in Circuits
➤NOTE: The resistors used were:
R
1
= 100Ω
R
2
= 330Ω
R
3
= 560Ω
These are the same resistors as were used in the
previous lab, and some of the data here originates in
lab 5.
Procedure
Series:
The current was the same—1.5 mA—no matter where it
was measured in the circuit.
Parallel:
Measurement Resistance Current Voltage
1 100 0.0156 1.574
2 330 0.0047 1.574
3 560 0.0028 1.574
123 67.5 0.0229 1.574
Discussion
In any resistance circuit—series, parallel, or both—the
voltage, current, and resistance are related by Ohm’s
Law:
V = IR
This pattern, and conclusion, should be apparent in
student data.
➤NOTE: The product of the resistances and
currents obtained experimentally will generally be
lower than the measured voltage. This is due to the
non-zero resistance of the ammeter. When the
meter is in the circuit, its own resistance lessens the
current through that circuit. With most meters, this
error should be less than 5% or so.
Exp 7- Kirchoff's Rules
Procedure
First circuit:
12
34
5
+
+
+
+
+
Second circuit:
+
+
+
+
+
1
24
3
5b1
b2
R (Ω) V (V) I (mA)
1 100 0.27 2.6
2 560 1.50 2.6
3 330 0.19 0.5
4 330 1.07 3.2
5 100 0.32 3.2
b1 1.573 2.6
b2 1.588 3.2
R (Ω) V (V) I (mA)
1 100 0.40 3.9
2 560 1.17 2.0
3 330 1.05 3.1
4 100 0.52 5.1
5 330 0.65 1.9
T 216 1.57 7.1