Question: In a glass bulb mercury arc rectifier the maximum current rating is restricted to___________?

• 1. 2000 A
• 2. 1500 A
• 3. 1000 A
• 4. 500 A

Question: In a mercury arc rectifier characteristic blue luminosity is due to_____________?

• 1. colour of mercury
• 2. ionization
• 3. high temperature
• 4. electron streams

Question: When a rectifier is loaded which of the following voltage drops take place ?

• 1. Voltage drop in transformer reactance
• 2. Voltage drop in resistance of transformer and smoothing chokes
• 3. Arc voltage drop
• 4. All of the above

Question: Which of the following mercury arc rectifier will deliver least undulating current?

• 1. Six-phase
• 2. Three-phase
• 3. Two-phase
• 4. Single-phase

Question: In a three-phase mercury arc rectifiers each anode conducts for____________?

• 1. one-third of a cycle
• 2. one-fourth of a cycle
• 3. one-half a cycle
• 4. two-third of a cycle

Question: In a mercury arc rectifier________ flow from anode to cathode.

• 1. ions
• 2. electrons
• 3. ions and electrons
• 4. any of the above

Question: A mercury arc rectifier possesses __________ regulation characteristics.

• 1. straight line
• 2. curved line
• 3. exponential
• 4. none of the above

Question: In a grid control of mercury arc rectifiers when the grid is made positive relative to cathode, then it the electrons on their may to anode.

• 1. accelerates
• 2. decelerates
• 3. any of the above
• 4. none of the above

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

• 1. The voltage regulation of the rec¬tifier should be low
• 2. In the output circuit there should be no harmonics
• 3. The power factor of the system should be high
• 4. all of the above

Question: It is the_________of the transformer on which the magnitude of angle of overlap depends?

• 1. resistance
• 2. capacitance
• 3. leakage reactance
• 4. any of the above