Deck 9: HVDC Transmission, DC Power Supplies, and Zener Diodes

Question 1

HVDC transmission has-------------------as compared to HVAC transmission.

A)smaller transformer size
B)smaller conductor size
C)higher corona loss
D)smaller power transfer capabilities

Answer 1

smaller conductor size

Question 2

The negative polarity is used in the monopolar link because it

A)uses less conductor size
B)is safer
C)produces less radio interference
D)has less resistance

Answer 2

produces less radio interference

Question 3

Which of the following can be a source of supply in dc power supplies?

A)battery
B)dry cell
C)full wave rectifier
D)all of the mentioned

Answer 3

all of the mentioned

Question 4

Which of the application's filters used for?

A)reducing ripples
B)increasing ripples
C)increasing phase change
D)increasing amplitude

Question 5

Which of the following represent a change of output voltage when load current is increased?

A)line regulation
B)load regulation
C)current regulation
D)voltage regulation

Question 6

Which of the following generate output voltage much closer to true value?

A)true generator
B)precision generator
C)output generator
D)accurate generator

Question 7

Why zener diodes are provided in dc supply?

A)for forward conduction
B)for reverse conduction
C)for reference voltage
D)for increasing amplitude

Question 8

Stability of output voltage is entirely depended on                              

A)stability of transformer
B)stability of zener diode
C)quality of wires
D)capacitor values

Question 9

For excellent stability, the zener diode is kept in temperature controlled casket.

Question 10

For instrumentation system, precision variable voltage-reference system is necessary.

Question 11

Which of the following can be used as a comparator?

A)zener diode
B)diode
C)operational amplifier
D)all of the mentioned

Question 12

Which of the following are not the standard value of Zener diodes?

A)5.1 v
B)5.6 v
C)5.8v
D)6.2v