a) Assemble the series resonant (also known as variable frequency resonant) circuit as shown below. Use a 50 mH coil as L in the parts kit, select a resistor of approximately 1 k ohm and a capacitor of 1 to a few nF. Measure the values of these components before assembly. Measure the coil resistance using a digital ohmmeter as well. Calculate the expected resonance frequency.

Series resonant circuit

b) Connect one oscilloscope probe across the voltage source and another oscilloscope across R, while simultaneously observing two signals on different oscilloscope channels. When changing the frequency, please pay attention to the amplitude and phase difference. If the voltage amplitude of the generator varies with frequency, it can be adjusted to keep it constant, otherwise please pay attention to its values at different frequencies. Obtain a sufficient number of data points to plot the resonance curve. Attempt to accurately determine the series resonant frequency at the peak of the curve and the frequency at the half power points on both sides of the maximum value. Also measure the phase shift between V s and V R at these three frequencies, as well as at several other frequencies on either side of the maximum frequency. 

C) By using the signal subtraction function of a digital oscilloscope, the voltage across the capacitor during resonance can also be measured. Please note that it is greater than the generator voltage. The ratio of these voltages is equal to the Q value of the circuit.