MCQOPTIONS
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MCQOPTIONS
This section includes 109 Mcqs, each offering curated multiple-choice questions to sharpen your Active Filter Circuits knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The ________ is (are) an adjustable voltage regulator. |
| A. | series 7800 ICs |
| B. | series 7900 ICs |
| C. | LM317 |
| D. | None of the above |
| Answer» D. None of the above | |
| 2. |
The series 7900 ICs are ________. |
| A. | positive voltage regulators |
| B. | negative voltage regulators |
| C. | both positive and negative voltage regulators |
| D. | adjustable-set voltage regulators |
| Answer» C. both positive and negative voltage regulators | |
| 3. |
The specification sheet for the 7812 fixed positive voltage regulator shows that the output voltage could be as low as ________ or as high as ________. |
| A. | 11.5 V, 12.5 V |
| B. | 11.2 V, 12.2 V |
| C. | 11 V, 13 V |
| D. | 8 V, 15 V |
| Answer» B. 11.2 V, 12.2 V | |
| 4. |
IC units provide regulation of ________. |
| A. | a fixed positive voltage |
| B. | a fixed negative voltage |
| C. | an adjustably set voltage |
| D. | All of the above |
| Answer» E. | |
| 5. |
Regulator IC units contain the circuitry for the ________. |
| A. | reference source |
| B. | comparator amplifier |
| C. | control device and overload protection |
| D. | All of the above |
| Answer» E. | |
| 6. |
A type of regulator circuit that is quite popular for its efficient transfer of power to the load is the ________. |
| A. | current-limiting voltage regulator |
| B. | switching regulator |
| C. | foldback limiting regulator |
| D. | op-amp series regulator |
| Answer» C. foldback limiting regulator | |
| 7. |
In a foldback configuration, limiting the current reduces ________, protecting the load from overcurrent as well as protecting the regulator. |
| A. | the output voltage |
| B. | the output current |
| C. | both the output voltage and output current |
| D. | None of the above |
| Answer» D. None of the above | |
| 8. |
In a current-limiting circuit, ________ provide(s) the limiting of the maximum load current. |
| A. | the Zener diode |
| B. | the short-circuit resistor Rsc |
| C. | the transistor Q1 |
| D. | both the short-circuit resistor Rsc and transistor Q2 |
| Answer» E. | |
| 9. |
The ________ the diode conduction time, the ________ the amount of the charging current through the capacitor filter. |
| A. | shorter, larger |
| B. | shorter, smaller |
| C. | longer, larger |
| D. | None of the above |
| Answer» B. shorter, smaller | |
| 10. |
The ________ values of capacitor filter provide ________ ripple and ________ average voltage. |
| A. | larger, more, higher |
| B. | smaller, less, lower |
| C. | smaller, more, higher |
| D. | larger, less, higher |
| Answer» E. | |
| 11. |
The frequency of the output voltage of a full-wave rectifier is ________ the frequency of its input voltage. |
| A. | the same as |
| B. | twice |
| C. | one-half |
| D. | one-third |
| Answer» C. one-half | |
| 12. |
In a full-wave rectifier, if no load were connected across the capacitor, the output voltage would ideally be a(n) ________. |
| A. | ac voltage |
| B. | constant dc voltage |
| C. | pulsating dc voltage |
| D. | ramp voltage |
| Answer» C. pulsating dc voltage | |
| 13. |
The charging and discharging of the capacitor filter take ________ of the period of the input voltage. |
| A. | 0.25 |
| B. | 0.5 |
| C. | 0.75 |
| D. | 1 |
| Answer» C. 0.75 | |
| 14. |
The ripple voltage Vr is a result of the ________. |
| A. | conduction of the diode(s) |
| B. | transformer windings |
| C. | charging and discharging of the capacitor |
| D. | load resistor |
| Answer» D. load resistor | |
| 15. |
The output of a loaded power supply is ________ that of the unloaded. |
| A. | the same as |
| B. | larger than |
| C. | smaller than |
| D. | None of the above |
| Answer» D. None of the above | |
| 16. |
In a full-wave rectifier, the dc voltage level is ________ the ripple voltage level. |
| A. | smaller than |
| B. | the same as |
| C. | larger than |
| D. | None of the above |
| Answer» D. None of the above | |
| 17. |
If the value of the full-load voltage is the same as the no-load voltage, the voltage regulation calculated is ________. |
| A. | 0% |
| B. | a negative percentage |
| C. | a positive percentage |
| D. | None of the above |
| Answer» B. a negative percentage | |
| 18. |
In a half-wave rectifier, the dc voltage level is ________ the ripple voltage level. |
| A. | smaller than |
| B. | the same as |
| C. | larger than |
| D. | None of the above |
| Answer» B. the same as | |
| 19. |
A full-wave rectified signal has ________ dc component and ________ ripple than (as) the half-wave rectified voltage. |
| A. | a larger, more |
| B. | a smaller, less |
| C. | the same, less |
| D. | a larger, less |
| Answer» E. | |
| 20. |
The ________ the voltage regulation, the ________ the operation of the voltage supply circuit. |
| A. | smaller, better |
| B. | larger, better |
| C. | smaller, worse |
| D. | None of the above |
| Answer» B. larger, better | |
| 21. |
The filter output voltage of a power supply ________ when load current is drawn from the supply. |
| A. | remains the same |
| B. | is increased |
| C. | is reduced |
| D. | None of the above |
| Answer» D. None of the above | |
| 22. |
A dc voltmeter reads the ________ while measuring a pulsating dc voltage. |
| A. | ac component of the signal |
| B. | average of the signal |
| C. | peak of the pulsating signal |
| D. | None of the above |
| Answer» C. peak of the pulsating signal | |
| 23. |
The ________ the ac variation with respect to the dc level, the ________ the filter circuit's operation. |
| A. | smaller, better |
| B. | larger, better |
| C. | smaller, worse |
| D. | None of the above |
| Answer» B. larger, better | |
| 24. |
The output resulting from a rectifier is a(n) ________. |
| A. | ac voltage |
| B. | pure dc voltage |
| C. | pulsating dc voltage |
| D. | None of the above |
| Answer» D. None of the above | |
| 25. |
A complete power supply has a ________. |
| A. | rectifier |
| B. | filter |
| C. | voltage regulator |
| D. | All of the above |
| Answer» E. | |
| 26. |
What are the typical values of Vref and Iadj for the LM317 adjustable voltage regulator? |
| A. | 1.0 V, 100 mA |
| B. | 1.5 V, 100 mA |
| C. | 1.25 V, 100 μA |
| D. | 1.25 V, 10 mA |
| Answer» D. 1.25 V, 10 mA | |
| 27. |
What regulated output voltage is provided for the following circuit elements: R1 = 15 k, R2 = 35 k, and VZ = 11.2 V? |
| A. | 16.50 V |
| B. | 17 V |
| C. | 17.35 V |
| D. | 18.25 V |
| Answer» C. 17.35 V | |
| 28. |
For a full-wave rectifier with ac ripple at 120 Hz, the impedance of a capacitor can be calculated using XC = ________. |
| A. | 0.707 ÷ C |
| B. | 1.414 ÷ C |
| C. | 1.3 ÷ C |
| D. | 0.785 ÷ C |
| Answer» D. 0.785 ÷ C | |
| 29. |
Calculate the dc voltage across a 2-k load for an RC filter section (R = 50 , C = 20 F). The dc voltage across the initial filter capacitor is Vdc = 50 V. |
| A. | 40.78 V |
| B. | 42.78 V |
| C. | 45.78 V |
| D. | 48.78 V |
| Answer» E. | |
| 30. |
What is the ratio of the peak ripple voltage level to its rms voltage level? |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» B. [B]. | |
| 31. |
Calculate the ripple voltage of a full-wave rectifier with a 75-F filter capacitor connected to a load drawing 40 mA. |
| A. | 1.20 V |
| B. | 1.28 V |
| C. | 1.32 V |
| D. | 1.41 V |
| Answer» C. 1.32 V | |
| 32. |
A ________ -wave rectified signal has less ripple than a ________ -wave rectified signal and is thus better to apply to a filter. |
| A. | full, half |
| B. | half, full |
| Answer» B. half, full | |
| 33. |
Calculate the voltage regulation of a power supply having VNL = 50 V and VFL = 48 V. |
| A. | 4.17% |
| B. | 5.2% |
| C. | 6.2% |
| D. | 7.1% |
| Answer» B. 5.2% | |
| 34. |
Calculate the ripple of a filter output having a 20-V dc component and a 1.7 Vr(rms) ac component. |
| A. | 6% |
| B. | 8.5% |
| C. | 85% |
| D. | 58% |
| Answer» C. 85% | |
| 35. |
A three-terminal regulator can be used with an external pass transistor to increase the total load current available. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 36. |
A switching regulator can be configured as a step-up or a step-down voltage regulator. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 37. |
For an IC regulator, the input voltage must be at least 2 V above the regulated output voltage. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 38. |
Under no-load, a shunt regulator has minimum current through the control element. |
| A. | True |
| B. | False |
| Answer» C. | |
| 39. |
A pass transistor may be used in a series regulator, as the current-carrying device. |
| A. | True |
| B. | False |
| Answer» C. | |
| 40. |
Line regulation is the percentage change in output voltage for a given change in input line current. |
| A. | True |
| B. | False |
| Answer» C. | |
| 41. |
Load regulation is the percentage change in line voltage for a change in load voltage. |
| A. | True |
| B. | False |
| Answer» C. | |
| 42. |
IC voltage regulators are sometimes called three-terminal regulators. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 43. |
Switching regulators are not very efficient. |
| A. | True |
| B. | False |
| Answer» C. | |
| 44. |
A basic voltage regulator consists largely of a reference source, an error detector, and a control device. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 45. |
The ________ regulator is less efficient than the ________ type, but offers inherent short-circuit protection. |
| A. | series, shunt |
| B. | shunt, series |
| Answer» C. | |
| 46. |
Refer to the given figure. If a solder splash shorted the ends of R1 to each other, |
| A. | the op-amp would fail. |
| B. | Q1 would open. |
| C. | the output voltage would not change. |
| D. | the zener would fail. |
| Answer» E. | |
| 47. |
Refer to the given figure. If the BE junction of Q1 opens, the output voltage VOUT will |
| A. | increase. |
| B. | decrease. |
| C. | remain the same. |
| Answer» C. remain the same. | |
| 48. |
Refer to the given figure. If the output of the circuit were to be a short circuit, what power rating would R1 need to have? |
| A. | 2.25 W |
| B. | 5 W |
| C. | 10 W |
| D. | 22.5 W |
| Answer» E. | |
| 49. |
Refer to the given figure. The purpose for the zener diode D1 is |
| A. | to supply a reference voltage. |
| B. | to amplify the error signal. |
| C. | to sense the error signal. |
| D. | to limit the input voltage to the circuit. |
| Answer» B. to amplify the error signal. | |
| 50. |
Refer to the given figure. If the load is short-circuited, what would be the maximum current through R1? |
| A. | 1 A |
| B. | 1.2 A |
| C. | 1.5 A |
| D. | 5 A |
| Answer» D. 5 A | |