Page 150 - Op Amps Design, Applications, and Troubleshooting

Review Questions 133

7. The value of C f in Figure 2.26(a) is the primary factor that sets the upper cutoff
frequency. (True or False) Explain why or why not.
8. If capacitor CQ in Figure 2.26(b) becomes open, what effect will this have on circuit
operation to the left of capacitor C 0?
9. If capacitor Q in Figure 2.26(b) becomes open, what happens to the DC voltage on the
output pin of the op amp? What happens to the IX voltage across R L?
10. Refer to Figure 2.32. As the wiper arm of R P is moved to the right, what happens to the
average current through R L?
11. Refer to Figure 2.32. If the wiper arm of R P is moved too far to the left, the output
waveform will start to clip. Explain which peak (positive or negative) is clipped and
why.
12. Refer to Figure 2.21. What happens to the average (i.e., DC) current through R L if R n
becomes open?
13. What is another name for a noninverting amplifier with a voltage gain of 1?
14. Can a standard 741 op amp be used to amplify a 33-kilohertz signal if the desired
voltage gain is 5 and the maximum peak output voltage swing is 11 volts? Explain
your answer.
15. While troubleshooting the circuit shown in Figure 2.27(a), you discover that the
voltage on the inverting (-) pin of the op amp is approximately 0 volts (with a normal
signal applied at the input). If you think this is normal, explain why. If you think it is
abnormal, what is the most likely defect?