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
Selenium rectifier can be operated at temperatures as high as
Selenium rectifier can be operated at temperatures as high as
In a mercury arc rectifier characteristic blue luminosity is due to
In a mercury arc rectifier characteristic blue luminosity is due to
The advantage of mercury arc rectifier is that
The advantage of mercury arc rectifier is that
A rotary converter operates at a
A rotary converter operates at a
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.?
In a mercury pool rectifier, the voltage drop across its electrodes
In a mercury pool rectifier, the voltage drop across its electrodes
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 which of the following equipment direct current is needed?
In which of the following equipment direct current is needed?
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
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?
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?
In selenium rectifiers efficiencies ranging from ______ to ______ percent are attainable
In selenium rectifiers efficiencies ranging from ______ to ______ percent are attainable
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
The efficiency of an electrolytic rectifier is nearly
The efficiency of an electrolytic rectifier is nearly
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.
To produce cathode spot in a mercury arc rectifier
To produce cathode spot in a mercury arc rectifier
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 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
In a mercury arc rectifier positive ions are attracted towards
In a mercury arc rectifier positive ions are attracted towards
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 ?
The metal rectifiers, as compared to mercury arc rectifiers
The metal rectifiers, as compared to mercury arc rectifiers
A commutating rectifier consists of commutator driven by
A commutating rectifier consists of commutator driven by
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?
The cathdde voltage drop, in a mercury arc rectifier, is due to
The cathdde voltage drop, in a mercury arc rectifier, is due to
Copper oxide rectifier is usually designed not to operate above
Copper oxide rectifier is usually designed not to operate above
The applications of selenium rectifiers are usually limited to potential of
The applications of selenium rectifiers are usually limited to potential of
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 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
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
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.
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?
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 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
Ageing of a selenium rectifier may change the output voltage by
Ageing of a selenium rectifier may change the output voltage by
In a mercury arc rectifier, the anode is usually made of
In a mercury arc rectifier, the anode is usually made of
In a rotary converter armature currents are
In a rotary converter armature currents are
A synchronous converter can be started
A synchronous converter can be started
A rotary converter combines the function of
A rotary converter combines the function of
In a mercury arc rectifier______ flow from anode to cathode
In a mercury arc rectifier______ flow from anode to cathode
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
A rotary converter is a single machine with
A rotary converter is a single machine with
Which of the following metals is generally manufactured by electrolysis process?
Which of the following metals is generally manufactured by electrolysis process?
Which of the following are the applications of D.C. system?
Which of the following are the applications of D.C. system?
The internal efficiency of a mercury arc rectifier depends on
The internal efficiency of a mercury arc rectifier depends on
The ionization potential of mercury is approximately
The ionization potential of mercury is approximately
In which of the following appUcations, direct current is absolutely essential ?
In which of the following appUcations, direct current is absolutely essential ?
Mercury, in arc rectifiers, is chosen for cathode because
Mercury, in arc rectifiers, is chosen for cathode because
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?
Which of the following is reversible in action?
Which of the following is reversible in action?
In a three-phase mercury arc rectifiers each anode conducts for
In a three-phase mercury arc rectifiers each anode conducts for
The efficiency of the copper oxide rectifier seldom exceeds
The efficiency of the copper oxide rectifier seldom exceeds
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.
The potential drop in the arc, in a mercury arc rectifier, varies
The potential drop in the arc, in a mercury arc rectifier, varies
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
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 ?
A mercury arc rectifier possesses ________ regulation characteristics
A mercury arc rectifier possesses ________ regulation characteristics
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
