211. If the load current drawn by unregulated power supply increases, the d.c. output voltage
A. increases
B. decreases
C. stays the same
D. none of the above
212. If a power- supply has no-load and full-load voltages of 30 V and 25 V respectively, then percentage voltage regulation is
A.10%
B.20%
C.15%
D. none of the above
213. A power supply has a voltage regulation of 1%. If the no-load voltage is 20V, what is the full-load voltage?
A. 20.8 V
B. 15.7 V
C. 18.6 V
D. 17.2 V
214. Two similar 15 V zeners are connected in series. What is the regulated output voltage?
A. 15 V
B. 7.5 V
C. 30 V
D. 45 V
215. A power supply can deliver a maximum rated current of 0.5 A at full-load output voltage of 20 V. What is the minimum load resistance that you can connect across the supply?
A. 10 52
B. 20 52
C. 15 52
D. 40 52
216. In a regulated power supply, two similar 15 V zeners are connected in series. The input voltage is 45 V d.c. If each zener has a maximum current rating of 300 mA, what should be the value of series resistance?
A. 10 SI
B. 50 SI
C. 25 52
D. 40 SI
217. A zener regulator ___ in the power supply.
A. increases the ripple
B. decreases the ripple
C. neither increases nor decreases ripple
D. data insufficient
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