Below are the answers key for the Multiple Choice Questions (MCQs) in Chapter 21: Power Supplies from the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco.
1. Pulsating dc.
2. All of the above are generally needed.
3. A TV broadcast transmitter.
4. It uses the whole transformer secondary for the entire ac input cycle.
5. Full-wave, center-tap.
6. The filter.
7. 52.7 V.
8. 70 V.
9. Poor regulation.
10. 28 V.
11. Twice that from a half-wave circuit.
12. A capacitor in parallel and a choke in series.
13. Use two capacitor/choke sections one after the other.
14. Parallel with the filter output, reverse-biased.
15. The filter capacitor(s) must be initially charged.
16. Diode failure.
17. The fuse will blow out right away.
18. A quick-break type.
19. Connected in parallel with filter capacitors.
20. Leave it alone and have a professional work on it.