A commutating rectifier consists of commutator driven by___________?

Related Mcqs:

1. Which of the following is the loss within the mercury arc rectifier chamber ?

   A. Voltage drop in arc
   B. Voltage drop at the anode
   C. Voltage drop at the cathode
   D. All of the above

2. Selenium rectifier can be operated at temperatures as high as____________?

   A. 25°C
   B. 40°C
   C. 60°C
   D. 75°C

3. The efficiency of the copper oxide rectifier seldom exceeds____________?

   A. 90 to 95%
   B. 85 to 90%
   C. 80 to 85%
   D. 65 to 75%

4. In a mercury arc rectifier characteristic blue luminosity is due to_____________?

   A. colour of mercury
   B. ionization
   C. high temperature
   D. electron streams

5. On which of the following factors the number of phases for which a rectifier should be designed depend ?

   A. The voltage regulation of the rec¬tifier should be low
   B. In the output circuit there should be no harmonics
   C. The power factor of the system should be high
   D. The rectifier supply transformer should be utilized to the best ad-vantage
   E. all of the above

6. Which of the following mercury arc rectifier will deliver least undulating current?

   A. Six-phase
   B. Three-phase
   C. Two-phase
   D. Single-phase

7. When a rectifier is loaded which of the following voltage drops take place ?

   A. Voltage drop in transformer reactance
   B. Voltage drop in resistance of transformer and smoothing chokes
   C. Arc voltage drop
   D. All of the above

8. The voltage drop between the anode and cathode, of a mercury arc rectifier comprises of the following_____________?

   A. anode drop and cathode drop
   B. anode drop and arc drop
   C. cathode drop and arc drop
   D. anode drop, cathode drop and arc drop

9. The internal efficiency of a mercury arc rectifier depends on___________?

   A. voltage only
   B. current only
   C. voltage and current
   D. r.m.s. value of current
   E. none of the above

10. The advantage of mercury arc rectifier is that________________?

    A. it is light in weight and occupies small floor space
    B. it has high efficiency
    C. it has high overload capacity
    D. it is comparatively noiseless
    E. all of the above