1. If N1/N2 = 2, and the primary voltage is 120 V, what is the secondary voltage?
a. 0 V
b. 36 V
c. 60 V
d. 240 V
c
2. In a step-down transformer, which is larger?
a. Primary voltage
b. Secondary voltage
c. Neither
d. No answer possible
a
3. A transformer has a turns ratio of 4: 1. What is the peak secondary voltage if 115 V rms is applied to the primary winding?
a. 40.7 V
b. 64.6 V
c. 163 V
d. 650 V
a
4. With a half-wave rectified voltage across the load resistor, load current flows for what part of a cycle?
a. 0 degrees
b. 90 degrees
c. 180 degrees
d. 360 degrees
c
5. Line voltage may be from 105 V rms to 125 rms in a half-wave rectifier. With a 5:1 step-down transformer, the maximum peak
load voltage is closest to
a. 21 V
b. 25 V
c. 29.6 V
d. 35.4 V
d
6. The voltage out of a bridge rectifier is a
a. Half-wave signal
b. Full-wave signal
c. Bridge-rectified signal
d. Sine wave
b
7. If the line voltage is 115 V rms, a turns ratio of 5: 1 means the rms secondary voltage is closest to
a. 15 V
b. 23 V
c. 30 V
d. 35 V
b
8. What is the peak load voltage in a full-wave rectifier if the secondary voltage is 20 V rms?
a. 0 V
b. 0.7 V
c. 14.1 V
d. 28.3 V
c
9. We want a peak load voltage of 40 V out of a bridge rectifier. What is the approximate rms value of secondary voltage?
a. 0 V
b. 14.4 V
c. 28.3 V
d. 56.6 V
c
10. With a full-wave rectified voltage across the load resistor, load current flows for what part of a cycle?
a. 0 degrees
b. 90 degrees
c. 180 degrees
d. 360 degrees
d
11. What is the peak load voltage out of a bridge rectifier for a secondary voltage of 15 V rms? (Use second approximation.)
a. 9.2 V
b. 15 V
c. 19.8 V
d. 24.3 V
c
12. If line frequency is 60 Hz, the output frequency of a half-wave rectifier is
a. 30 Hz
b. 60 Hz
c. 120 Hz
d. 240 Hz
b
13. If line frequency is 60 Hz, the output frequency of a bridge rectifier is
a. 30 Hz
b. 60 Hz
c. 120 Hz
d. 240 Hz
c
14. With the same secondary voltage and filter, which has the most ripple?
a. Half-wave rectifier
b. Full-wave rectifier
c. Bridge rectifier
d. Impossible to say
a
15. With the same secondary voltage and filter, which produces the least load voltage?
a. Half-wave rectifier
b. Full-wave rectifier
c. Bridge rectifier
d. Impossible to say
b
16. If the filtered load current is 10 mA, which of the following has a diode current of 10 mA?
a. Half-wave rectifier
b. Full-wave rectifier
c. Bridge rectifier
d. Impossible to say
a
17. If the load current is 5 mA and the filter capacitance is 1000uF, what is the peak-to-peak ripple out of a bridge rectifier?
a. 21.3 pV
b. 56.3 nV
c. 21.3 mV
d. 41.7 mV
d
18. The diodes in a bridge rectifier each have a maximum dc current rating of 2 A. This means the dc load current can have a
maximum value of
a. 1 A
b. 2 A
c. 4 A
d. 8 A
c
19. What is the PIV across each diode of a bridge rectifier with a secondary voltage of 20 V rms?
a. 14.1 V
b. 20 V
c. 28.3 V
d. 34 V
c
20. If the secondary voltage increases in a bridge rectifier with a capacitor-input filter, the load voltage will
a. Decrease
b. Stay the same
c. Increase
d. None of these
c
21. If the filter capacitance is increased, the ripple will
a. Decrease
b. Stay the same
c. Increase
d. None of these
a
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