MCQOPTIONS
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MCQOPTIONS
This section includes 23 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Devices knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In the Wien bridge oscillator with R = R = R and C = C = C, a ratio of R to R will provide sufficient loop gain for the circuit to oscillate. |
| A. | 0 |
| B. | 0.5 |
| C. | 1 |
| D. | 2 |
| Answer» E. | |
| 2. |
For a Wien-bridge oscillator, resonance occurs when V/V = 1. |
| A. | True |
| B. | False |
| Answer» C. | |
| 3. |
An amplifier is stable if the absolute magnitude of A is ________. |
| A. | less than 1 |
| B. | greater than 1 |
| C. | None of the above |
| Answer» C. None of the above | |
| 4. |
In the Colpitts oscillator, the elements X and X are ________ and X is a(n) ________. |
| A. | inductors, capacitor |
| B. | capacitors, inductor |
| C. | capacitors, resistor |
| D. | inductors, resistor |
| Answer» C. capacitors, resistor | |
| 5. |
In a Hartley oscillator, the elements X and X are ________ and X is a(n) ________. |
| A. | inductors, capacitor |
| B. | capacitors, inductor |
| C. | capacitors, resistor |
| D. | inductors, resistor |
| Answer» B. capacitors, inductor | |
| 6. |
With feedback, , the overall gain of the circuit is reduced by a factor ________ where A is the gain without the feedback. |
| A. | A |
| B. | A |
| C. | 1 + |
| D. | A |
| Answer» E. | |
| 7. |
Calculate the value of C = C for the Wien bridge oscillator to operate at a frequency of 20 kHz. Assume R = R = 50 k and R = 3R = 600? |
| A. | 1.59 pF |
| B. | 15.9 pF |
| C. | 159 pF |
| D. | 1.59 nF |
| Answer» D. 1.59 nF | |
| 8. |
Only the condition A = ________ must be satisfied for self-sustained oscillations to result. |
| A. | 0 |
| B. | –1 |
| C. | 1 |
| D. | None of the above |
| Answer» D. None of the above | |
| 9. |
At what phase shift is the magnitude of A at its maximum in the Nyquist plot? |
| A. | 90º |
| B. | 180º |
| C. | 270º |
| D. | 0º |
| Answer» C. 270º | |
| 10. |
Referring to this figure, calculate the voltage gain without feedback for the following circuit values: R = 4 k, R = 1 k, R = 15 k, and g= 5000 μS. |
| A. | –20.0 |
| B. | –21.5 |
| C. | –23.5 |
| D. | –25.5 |
| Answer» B. –21.5 | |
| 11. |
An amplifier with a gain of –500 and a feedback of = –0.1 has a gain change of 15% due to temperature. Calculate the change in gain of the feedback amplifier. |
| A. | 0.2% |
| B. | 0.3% |
| C. | 0.4% |
| D. | 0.5% |
| Answer» C. 0.4% | |
| 12. |
Calculate the f of a lead-lag network if R = R = 6.8 k, and C = C = 0.05 F. |
| A. | 468 Hz |
| B. | 4.68 kHz |
| C. | 46.8 kHz |
| D. | 468 kHz |
| Answer» B. 4.68 kHz | |
| 13. |
Given g = 5000 S, r = 40 k, R = 10 k, and A = 35. Determine the value of R for oscillator operation at 1 kHz. |
| A. | 8.05 k |
| B. | 8.48 k |
| C. | 10.8 k |
| D. | 12.3 k |
| Answer» C. 10.8 k | |
| 14. |
Referring to this figure, calculate the voltage gain with the feedback for the following circuit values: R = 4 k, R = 1 k, R = 15 k, and g = 5000 μS. |
| A. | –11.2 |
| B. | –8.57 |
| C. | –6.75 |
| D. | –3.25 |
| Answer» C. –6.75 | |
| 15. |
Referring to this figure, calculate the amplification gain where the op-amp gain (A) is 200,000, R = 1.5 k, and R = 400 . |
| A. | 4.25 |
| B. | 4.50 |
| C. | 4.75 |
| D. | 5.00 |
| Answer» D. 5.00 | |
| 16. |
Referring to this figure, calculate the voltage gain with feedback A. |
| A. | –4.85 |
| B. | –4.20 |
| C. | –4.17 |
| D. | –4.00 |
| Answer» D. –4.00 | |
| 17. |
At what phase shift is the magnitude of A at its minimum in the Nyquist plot? |
| A. | 90º |
| B. | 180º |
| C. | 270º |
| D. | 0º |
| Answer» E. | |
| 18. |
Determine the output impedance with feedback for a voltage-series feedback having A = –100, R = 15 k, Ro = 20 k, and a feedback of = –0.25. |
| A. | 0.2 k |
| B. | 392.16 |
| C. | 1.82 k |
| D. | 769.23 |
| Answer» E. | |
| 19. |
Determine the voltage gain with feedback for a voltage-series feedback having A = –100, R = 15 k, R = 20 k, and a feedback of = –0.25. |
| A. | 3.85 |
| B. | –3.85 |
| C. | –9.09 |
| D. | 9.09 |
| Answer» C. –9.09 | |
| 20. |
Calculate the resonant frequency of this Wien bridge oscillator if R = 25 k, R = 40 k, C = 0.001 F, and C = 0.002 F. |
| A. | 1560.3 Hz |
| B. | 1779.4 Hz |
| C. | 3120.7 Hz |
| D. | 3558.8 Hz |
| Answer» E. | |
| 21. |
In the IC phase-shift oscillator, what should the ratio of feedback resistor R to R be? |
| A. | Zero |
| B. | Greater than –29 |
| C. | Less than 29 |
| D. | Any value |
| Answer» C. Less than 29 | |
| 22. |
Referring to this figure, calculate the amplification gain with feedback for the following circuit values: R = 80 k, R= 20 k, R = 10 k, R = 61 k, and g = 4000 μS. |
| A. | –4.36 |
| B. | –4.25 |
| C. | –6.35 |
| D. | –20.85 |
| Answer» B. –4.25 | |
| 23. |
Determine the input impedance with feedback for a voltage-series feedback having A = –100, R = 15 k, R = 20 k, and a feedback of = –0.25. |
| A. | 110 k |
| B. | 290 k |
| C. | 390 k |
| D. | 510 k |
| Answer» D. 510 k | |