1.  Open the Worksheet and fill in the header information.

2.  Turn on the oscilloscope and the function generator, making the following adjustments on the generator: Frequency = 100 hertz (use the 100 Hz button), Square Wave () button in, and Amplitude at about 9 o'clock. Connect the output directly to the 'scope at Channel A . Use DC coupling on Channel A.

3.  Make appropriate adjustments on the 'scope to obtain a good, stable trace, then adjust the function generator amplitude control until a square wave of 2 volts peak-peak amplitude is obtained. Record the p-p amplitude and measured period of this signal in cells D12:D13 on the Worksheet, and calculate the frequency (don't forget about the calibration knobs) in cell D14.

4.  Hook up a circuit on the breadboard with the 0.1 µF capacitor and the 10 kΩ resistor in series as shown in Fig. 8-4; connect the Function Generator output across the R-C string.

5.  Connect the 'scope across the capacitor, making sure to observe polarity: black-to-black! Next, make appropriate adjustments to obtain a clean stable trace. Measure and record the time it takes for the capacitor voltage to reach 63% of its peak or final value in cell D18. This value is defined to be the time constant of the circuit. Calculate the theoretical value, as given by τ = RC, and enter the value in cell D19. Compute the percentage error and enter in cell D20.

6.  Hook up the same type of circuit with the 0.01 µF capacitor and the 100 kΩ resistor in series.

7.  Repeat the measurements of step 5, and record the value of the time constant obtained in cell D24, the theoretical value in cell D25, and the percentage error in cell D26.

8.  Repeat measurements of step 5, using the 0.1 µF capacitor and with the unknown resistor instead of the 10 kΩ. Measure the time constant and enter in cell D30. Enter the known capacitance in cell D31, and compute the unknown resistance and enter its value in cell D33.

9.  Measure the time constant for each of the other two R-C combinations not examined previously: 0.01 µF/10 kΩ and 0.l µF/100 kΩ. You may have to change the frequency accordingly to get a good "shoulder" on the output waveform. Record the frequency in each case in cells D37 and D44, respectively.

10.  Measure the time constants and enter the values in cells D38 and D45, respectively.