The ionization potential of mercury is approximately_____________?

Related Mcqs:

1. In mercury arc rectifiers having grid, the arc can be struck between anode and cathode only when the grid attains a certain potential, this potential being known as______________?

   A. maximum grid voltage
   B. critical grid voltage
   C. any of the above
   D. none of the above

2. The potential drop in the arc, in a mercury arc rectifier, varies_____________?

   A. 0.05 V to 0.2 V per cm length of the arc
   B. 0.5 V to 1.5 V per cm length of the arc
   C. 2 V to 3.5 V per cm length of the arc
   D. none of the above

3. 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

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. 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.

   A. accelerates
   B. decelerates
   C. any of the above
   D. none 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. 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

8. 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

9. 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

10. The cathdde voltage drop, in a mercury arc rectifier, is due to_____________?

    A. expenditure of energy in ionization
    B. surface resistance
    C. expenditure of energy in overcoming the electrostatic field
    D. expenditure of energy in liberating electrons from the mercury