Which of the following are the applications of D.C. system?
Which of the following are the applications of D.C. system?
In a rotary converter armature currents are
In a rotary converter armature currents are
On which of the following factors the number of phases for which a rectifier should be designed depends?
On which of the following factors the number of phases for which a rectifier should be designed depends?
The potential drop in the arc, in a mercury arc rectifier, varies
The potential drop in the arc, in a mercury arc rectifier, varies
A synchronous converter can be started
A synchronous converter can be started
The advantage of mercury arc rectifier is that
The advantage of mercury arc rectifier is that
The ignited or auxiliary anode in mercury arc rectifier is made of
The ignited or auxiliary anode in mercury arc rectifier is made of
The efficiency of the copper oxide rectifier seldom exceeds
The efficiency of the copper oxide rectifier seldom exceeds
Mercury, in arc rectifiers, is chosen for cathode because
Mercury, in arc rectifiers, is chosen for cathode because
The efficiency of an electrolytic rectifier is nearly
The efficiency of an electrolytic rectifier is nearly
To produce cathode spot in a mercury arc rectifier
To produce cathode spot in a mercury arc rectifier
In a mercury arc rectifier positive ions are attracted towards
In a mercury arc rectifier positive ions are attracted towards
Ageing of a selenium rectifier may change the output voltage by
Ageing of a selenium rectifier may change the output voltage by
In a three-phase mercury arc rectifiers each anode conducts for
In a three-phase mercury arc rectifiers each anode conducts for
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.
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.
Which of the following rectifiers are primarily used for charging of low voltage batteries from AC. supply?
Which of the following rectifiers are primarily used for charging of low voltage batteries from AC. supply?
Which of the following is reversible in action?
Which of the following is reversible in action?
A commutating rectifier consists of commutator driven by
A commutating rectifier consists of commutator driven by
With a motor converter it is possible to obtain D.C. voltage only upto
With a motor converter it is possible to obtain D.C. voltage only upto
Which of the following is the loss within the mercury arc rectifier chamber?
Which of the following is the loss within the mercury arc rectifier chamber?
Which of the following mercury arc rectifier will deliver least undulating current?
Which of the following mercury arc rectifier will deliver least undulating current?
In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of
In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of
In a glass bulb mercury arc rectifier the maximum current rating is restricted to
In a glass bulb mercury arc rectifier the maximum current rating is restricted to
In a rotary converter I2R losses as compared to a D.C. generator of the same size will be
In a rotary converter I2R losses as compared to a D.C. generator of the same size will be
Glass rectifiers are usually made into units capable of D.C. output (maximum continuous rating) of
Glass rectifiers are usually made into units capable of D.C. output (maximum continuous rating) of
The metal rectifiers, as compared to mercury arc rectifiers
The metal rectifiers, as compared to mercury arc rectifiers
The voltage drop between the anode and cathode, of a mercury arc rectifier comprises of the following
The voltage drop between the anode and cathode, of a mercury arc rectifier comprises of the following
Selenium rectifier can be operated at temperatures as high as
Selenium rectifier can be operated at temperatures as high as
The applications of selenium rectifiers are usually limited to potential of
The applications of selenium rectifiers are usually limited to potential of
Which of the following metals is generally manufactured by electrolysis process?
Which of the following metals is generally manufactured by electrolysis process?
The cathdde voltage drop, in a mercury arc rectifier, is due to
The cathdde voltage drop, in a mercury arc rectifier, is due to
In phase-shift control method the control is carried out by varying the of grid voltage.
In phase-shift control method the control is carried out by varying the of grid voltage.
In a mercury pool rectifier, the voltage drop across its electrodes
In a mercury pool rectifier, the voltage drop across its electrodes
The voltage drop at anode, in a mercury arc rectifier is due to
The voltage drop at anode, in a mercury arc rectifier is due to
It is the_______of the transformer on which the magnitude of angle of overlap depends.
It is the_______of the transformer on which the magnitude of angle of overlap depends.
Normally, which of the following is used, when a large-scale conversion from AC. to D.C. power is required?
Normally, which of the following is used, when a large-scale conversion from AC. to D.C. power is required?
A mercury arc rectifier possesses ________ regulation characteristics
A mercury arc rectifier possesses ________ regulation characteristics
The metal rectifiers are preferred to valve rectifiers due to which of the following advantages ?
The metal rectifiers are preferred to valve rectifiers due to which of the following advantages ?
The ionization potential of mercury is approximately
The ionization potential of mercury is approximately
In which of the following equipment direct current is needed?
In which of the following equipment direct current is needed?
In a mercury arc rectifier______ flow from anode to cathode
In a mercury arc rectifier______ flow from anode to cathode
The internal efficiency of a mercury arc rectifier depends on
The internal efficiency of a mercury arc rectifier depends on
In a mercury arc rectifier characteristic blue luminosity is due to
In a mercury arc rectifier characteristic blue luminosity is due to
Copper oxide rectifier is usually designed not to operate above
Copper oxide rectifier is usually designed not to operate above
In a single phase rotary converter the number of slip rings will be
In a single phase rotary converter the number of slip rings will be
In a mercury arc rectifier, the anode is usually made of
In a mercury arc rectifier, the anode is usually made of
Which of the following methods may be used to convert A.C. system to D.C.?
Which of the following methods may be used to convert A.C. system to D.C.?
Which of the following AC. motors is usually used in large motor-generator sets?
Which of the following AC. motors is usually used in large motor-generator sets?
When a rectifier is loaded which of the following voltage drops take place ?
When a rectifier is loaded which of the following voltage drops take place ?
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
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 rotary converter operates at a
A rotary converter operates at a
A rotary converter in general construction and design, is more or less like
A rotary converter in general construction and design, is more or less like
In selenium rectifiers efficiencies ranging from ______ to ______ percent are attainable
In selenium rectifiers efficiencies ranging from ______ to ______ percent are attainable
If cathode and anode connections in a mercury arc rectifier are inter changed
If cathode and anode connections in a mercury arc rectifier are inter changed
A rotary converter is a single machine with
A rotary converter is a single machine with
Which of the following rectifiers have been used extensively in supplying direct current for electroplating?
Which of the following rectifiers have been used extensively in supplying direct current for electroplating?
In which of the following appUcations, direct current is absolutely essential ?
In which of the following appUcations, direct current is absolutely essential ?
A rotary converter combines the function of
A rotary converter combines the function of
