Please find here the answers for the StudentZone article June 2018.

**Question 1:**

Using equations (5) and (6) determine the impedance (Z_{circuit}) and phase (θ) relationship of the current relative to the voltage for a RC circuit by replacing the A and B variables with proper values.

**Answer 1:**

We consider the following equations for RC circuit:

The impedance of the capacitor is:

The impedance of the resistor is:

Therefore, we can compute the circuit impedance as follows:

Where: _{ }is known as the capacitive reactance of the capacitor.

**Question 2:**

For RC circuit in Figure 6, measure the time difference and calculate the phase θ offset at 1000 Hz frequency.

**Answer 2:**

Taking into consideration the setup made for the RC circuit measurements, additional steps must be followed:

- Set AWG CHA to 1000 Hz and the time / div to 0.2 msec/div.
- Put a first marker at the neg. to pos. zero crossing location for the CA-V ( V
_{R1}+ V_{C1}) signal. Put a second marker at the nearest neg. to pos. zero crossing location for the Math ( V_{R1}) signal. Record the time difference (∆t) and calculate the phase angle(θ). Note ∆t maybe a negative number. Does this mean the phase angle leads or lags?

To remove the markers for the next measurement click on the red Stop button.

- Put a first marker at the neg. to pos. zero crossing location for the CA-V ( V
_{R1}+ V_{C1}) signal. Put a second marker at the nearest neg. to pos. zero crossing location for the CB-V ( V_{C1}) signal. Record the time difference (∆t) and calculate the phase angle (θ). - Put a first marker at the neg. to pos. zero crossing location for the Math ( V
_{R1}) signal. Put a second marker at the nearest neg. to pos. zero crossing location for the CB-V ( V_{C1}) signal. Record the time difference and calculate the phase angle.