Electronic Devices-Voltage Regulators
Electronic Devices-Voltage Regulators
11. What is the ratio of the period of the output voltage to the period of the input voltage in a full-wave rectifier?
- 0
- 0.5
- 1
- 2
12. If the value of full-load voltage is the same as the no-load voltage, the voltage regulation calculated is ________ %, which is the best expected.
- 0
- 1
- 99
- 100
13. Calculate the ripple of a filter output having a 20-V dc component and a 1.7 Vr(rms) ac component.
- 6%
- 8.5%
- 85%
- 58%
14. A switching regulator that is configured as a voltage-inverter produces what type of output?
- an ac output with opposite phase to the input ac
- a dc output that is the negative of the dc input voltage
- an output that is a higher voltage than the input voltage
- an ac output from a dc input voltage
15. In Figure 17-1(a)(see question 6), the purpose of R1 is to
- provide a reference voltage.
- limit current through the diode.
- limit voltage to the op-amp.
- provide output voltage sampling.
16. For a full-wave rectifier with ac ripple at 120 Hz, the impedance of a capacitor can be calculated using XC = ________.
- 0.707 ÷ C
- 1.414 ÷ C
- 1.3 ÷ C
- 0.785 ÷ C
17. What is the purpose of an additional RC filter section in a power supply circuit?
- Increase the dc voltage component
- Increase the ac voltage component
- Decrease the ac voltage component
- None of the above
18. In which period is the capacitor filter charged in a full-wave rectifier?
- The time during the positive cycle
- The time during which the diodes are not conducting
- The time during which the diode(s) is (are) conducting
- The time during the negative cycle
19. The ________ regulator is less efficient than the ________ type, but offers inherent short-circuit protection.
- series, shunt
- shunt, series
20. In which of the following applications is a pulsating dc voltage suitable?
- Battery charger
- Radio
- Stereo system
- Computer