the Lab12
Measuring Inductance of an Inductor
Instructor:
Dr. Mohebi
Jiajie Huo(Jacky)
Member:
Ruihong Xiao
TEJ Shiwakoti
Anthony Hernandez
Dana Saiez
Rneiang Ye
WAJIH RAHMAN
2. introduction
In this experiment, we are generally focusing on measuring the
inductance of an inductor and compare the experimental one with
the theoretical one.
2
2
1. L=sqrt((R/x) -(r+R) )/2pi*f, while f refers to the frequency of
the ac resource, R refers to the resistance of the resistor, r
refers to the resistance of the inductor. x refers to the
potential difference between point B and point C.
3. Procedure.
Measure the wire resistance of the inductor , and we got
r=2.3.
2. Assembled the circuit shown above and adjust the generator.
We got R=100, and the changed the frequency of the
generator to 3.48KHz.
3. Measure the potential difference across the inductor, so
Vac=0.848V
4. Measure the potential difference between the generator,
Vab=1V.
5. Read the potential difference across points C and B, and it is
x=0.506V.
6. Subsititute the measured values into the formula to determine
the inductance L, and we got L=0.0127H.
7. Repeat the measurement for another value of resistance, with
the same frequency.
8. Repeat the measurement for another value of frequency and
the same resistance.
1.
9. Compare the result for different values of resistance the and
frequency.
10.
Compare potential drop across the inductor with
that across the resistor, find out which one is greater. We find
that the potential drop is larger between the resistance R, and it
makes sense because the resistance of R is greater than that of r.
11. Calculate the inductive reactance of the inductor for each
case.
12.
Calculate the impedance of the circuit.
13.
Calculate the rms current in the circuit
14. Try to insert a metal core inside the coil, and find out the
change of the inductance. And we found that the inductance of
it had increased.
2. Data and result.
f(KHz)
3.48
3.48
4.243
R()
100
150
100
r()
Uab(V)
2.3
2.3
2.3
1
1
1
Uac(V)
0.848
0.724
0.88
Ubc(V)
0.506
0.66
0.42
Ltheo(H)
Lexp(H)
6. Discussion and conclusion.
In this experiment, we use the battery and the resistance and
the bulb to prove the Ohms law. However, in the result, we find
that the resistor is a ohmic device and it obeys Ohms law, and we
found the difference of the experimental and actual resistance is
30%. On the other hand, the bulb do not obey Ohms law. We
found that this result appeared due to the bulb is not a Ohm device
and its internal resistance is changing when its temperature is
changing. And the change of the temperature may due to the
change of the current. Above all, this experiment is successful.