where 𝑓 is the generator frequency in hertz and 𝐿 is the inductance in henrys.
2.2 mH
From your kit, retrieve the 4.7 mH inductor and a 1 kW resistor. You will be loaned a 2.2 mH inductor by a lab tutor. You will not be able to measure their inductance with the DMM - only measure and record the value of resistor R1.
Step 4
Step 6
Step 5
Step 5
Step 4
Using the inductive reactance found in step 5, compute the inductance using the equation
𝑋𝐿=𝑉𝐿𝐼
𝑉𝐿=𝑋𝐿𝐼
To observe the voltage across R1, which is proportional to the current in the circuit, use the Math function of the DSO to perform the operation "Channel 1 - Channel 2". You may need to position and scale the display using the Math position and scale knobs. You should observe that the resistor voltage (and therefore inductor current) is lagging the inductor voltage by 90º. 
The circuit is a series circuit, so the current in the resistor is the identical current seen by the inductor. You can find this current easily by applying Ohm's Law to the resistor. Measure the RMS voltage across the resistor, VR1 , using the DMM on AC Voltage mode. Record the measured voltage in Table 7-2 in the row labelled Inductor L1. Compute the current in the circuit by dividing the measured voltage by the resistance of  R1 and enter the value in Table 7-2.
Figure 7-2
Table 7-2
Construct the circuit shown in Figure 7-2. Set the FG for a 20 kHz sine wave with a 1.0 V RMS output. Connect the DSO as shown. Check the frequency and voltage with the DSO.
When a sine wave is applied to an inductor, a voltage is induced across the inductor as given by Faraday's Law. When the change in current is a maximum, the largest induced voltage appears across the inductor. This is illustrated in Figure 7-1.
Figure 7-1
Table 7-1
Measure the RMS voltage across the inductor, VL1. Record this voltage in Table 7-2. Then use this voltage to compute the inductive reactance using Ohm's Law:
Enter this computed value of the inductive reactance in Table 7-2.
Enter the computed inductance in Table 7-2. This value should agree with the value marked on the inductor.
Repeat steps 4, 5, and 6 using inductor L2. Enter the data in Table 7-2 in the row labelled Inductor L2.
Now connect L1 in series with L2. The equivalent inductive reactance and inductance can be found for the series connection by measuring across both inductors as if they were one inductor. Enter the data in Table 7-3 in the row
(a) Find the current in the circuit by measuring the voltage across the resistor (as before) and dividing by the resistance. Enter the measured voltage and the current you compute in Table 7-3.
(b) Measure the voltage across both inductors. Enter this voltage in Table 7-3. Then use Ohm's Law to find the inductive reactance of both inductors.
Table 7-3
Connect the inductors in parallel and repeat step 8. Assume the parallel inductors are one equivalent inductor for the measurements. Enter the data in Table 7-3 in the row labelled Parallel Inductors.