Rectifiers And Converters Mcqs – (Electrical Engineering) MCQs Latest For FPSC, PPSC, NTS, KPPSC, SPSC & Other Tests

Rectifiers And Converters Mcqs – (Electrical Engineering) MCQs Latest For FPSC, PPSC, NTS, KPPSC, SPSC & Other Tests

Rectifiers And Converters Mcqs - (Electrical Engineering) MCQs Latest For FPSC, PPSC, NTS, KPPSC, SPSC & Other Tests
Rectifiers And Converters Mcqs

Rectifiers And Converters Mcqs “. Tab this page to check “Latest Rectifiers And Converters MCQs” for the preparation of competitive mcqs, FPSC mcqs, PPSC mcqs, SPSC mcqs, KPPSC mcqs, AJKPSC mcqs, BPSC mcqs, NTS mcqs, PTS mcqs, OTS mcqs, Atomic Energy mcqs, Pak Army mcqs, Pak Navy mcqs, CTS mcqs, ETEA mcqs and others. The most occurred mcqs of Rectifiers And Converters in past papers. Past papers of Rectifiers And Converters mcqs. Past papers of Rectifiers And Converters MCQs. Mcqs are the necessary part of any competitive / job related exams. The Rectifiers And Converters mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Rectifiers And Converters mcqs. The Important series of Rectifiers And Converters Mcqs are given below:



Which of the following methods may be used to convert A.C. system to D.C ?

A. Motor converters
B. Rectifiers
C. Motor-generator sets
D. Rotary converters
E. All of the above

A synchronous converter can be started______________?

A. from AC. side as induction motor
B. by means of a small auxiliary motor
C. from D.C. side as D.C. motor
D. any of the above methods
E. none of the above methods

Which of the following are the applications of D.C. system ?

A. Arc welding
B. Battery charging work
C. Electrolytic and electro-chemical processes
D. Arc lamps for search lights
E. All of the above

In a single phase rotary converter the number of slip rings will be_____________?

A. two
B. four
C. three
D. six
E. none

A rotary converter combines the function of____________?

A. a D.C. series motor and a D.C. generator
B. a synchronous motor and a D.C. generator
C. an induction motor and a D.C. generator
D. none of the above

With a motor converter it is possible to obtain D.C. voltage only upto__________?

A. 600—800 V
B. 200-100 V
C. 1000—1200 V
D. 1700—2000 V

Which of the following is reversible in action ?

A. Motor converter
B. Motor generator set
C. Rotary converter
D. Any of the above
E. None of the above

A rotary converter is a single machine with______________?

A. one armature and one field
B. one armature and two fields
C. two armatures and one field
D. none of the above

A rotary converter in general construction and design, is more or less like___________?

A. an induction motor
B. a transformer
C. an alternator
D. any D.C. machine

Which of the following metals is generally manufactured by electrolysis process ?

A. Copper
B. Aluminium
C. Load
D. Zinc
E. None of the above

Normally, which of the following is used, when a large-scale conversion from AC. to D.C. power is required ?

A. Motor-generator set
B. Rotary converter
C. Motor converter
D. Mercury arc rectifier

A rotary converter operates at a______________?

A. zero power factor
B. high power factor
C. low power factor
D. none of the above

In a rotary converter armature currents are______________?

A. a.c. only
B. d.c. only
C. partly a.c. and partly d.c.

In which of the following appUcations, direct current is absolutely essential ?

A. Traction
B. Electrolysis
C. Variable speed operation
D. Illumination

In a mercury arc rectifier positive ions are attracted towards______________?

A. shell bottom
B. cathode
C. anode
D. mercury pool

In which of the following equipment direct current is needed ?

A. Relays
B. Telephones
C. Time switches
D. All of the above

Which of the following AC. motors is usually used in large motor-generator sets?

A. Synchronous motor
B. Slip ring induction motor
C. Squirrel cage induction motor
D. Any of the above

In a rotary converter I2R losses as compared to a D.C. generator of the same size will be___________?

A. double
B. less
C. same
D. three times

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

A. 0.5 V to 1.5 V per cm length of the arc
B. 0.05 V to 0.2 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

Mercury, in arc rectifiers, is chosen for cathode because________________?

A. its ionization potential is relatively low
B. its boiling point and specific heat are low
C. its atomic weight is quite high
D. it remains in liquid state at ordi¬nary temperature
E. all of the above

Glass rectifiers are usually made into units capable of D.C. output (maximum continuous rating) of _____________?

A. 200 A at 200 V
B. 100 A at 100 V
C. 300 A at 300 V
D. 400 A at 400 V
E. 500 A at 500 V

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

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

To produce cathode spot in a mercury arc rectifier______________?

A. tube is evacuated
B. anode is heated
C. an auxiliary electrode is used
D. low mercury vapour pressures are used

The advantage of mercury arc rectifier is that________________?

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

The internal efficiency of a mercury arc rectifier depends on___________?

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

In a mercury pool rectifier, the voltage drop across its electrodes___________?

A. is inversely proportional to load
B. is directly proportional to load
C. varies exponentially with the load current
D. is almost independent of load current

If cathode and anode connections in a mercury arc rectifier are inter changed_____________?

A. the rectifier will not operate
B. the rectifier will operate at reduced efficiency
C. both ion and electron streams will move in the same direction
D. internal losses will be reduced

The voltage drop at anode, in a mercury arc rectifier is due to_____________?

A. high ionization potential
B. self restoring property of mercury
C. energy spent in overcoming the electrostatic field
D. high temperature inside the rectifier

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

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

The ionization potential of mercury is approximately_____________?

A. 8.4 V
B. 5.4 V
C. 10.4 V
D. 16.4 V

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

A. 1500 A
B. 2000 A
C. 1000 A
D. 500 A

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

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

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

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

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

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

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

A. one-third of a cycle
B. one-half a cycle
C. one-fourth of a cycle
D. two-third of a cycle

In a mercury arc rectifier________ flow from anode to cathode

A. ions
B. ions and electrons
C. electrons
D. any of the above

A mercury arc rectifier possesses __________ regulation characteristics

A. curved line
B. straight line
C. exponential
D. none of the above

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. Both of the above
D. none of the above

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. The power factor of the system should be high
C. In the output circuit there should be no harmonics
D. The rectifier supply transformer should be utilized to the best ad-vantage
E. all of the above

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

A. capacitance
B. resistance
C. leakage reactance
D. any of the above

In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of______________?

A. synchronous motor
B. shunt motor
C. induction regulator
D. synchronous generator

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. both of the above
D. none of the above

Which of the following statement is incorrect ?

A. Copper oxide rectifier is a linear device
B. Copper oxide rectifier has a low efficiency
C. Copper oxide rectifier is not a perfect rectifier
D. Copper oxide rectifier finds use in control circuits
E. Copper oxide rectifier is not stable during early life

In phase-shift control method the control is carried out by varying the of grid voltage

A. polarity
B. magnitude
C. phase
D. any of the above
E. none of the above

The metal rectifiers are preferred to valve rectifiers due to which of the following advantages ?

A. They do not require any voltage for filament heating
B. They are mechanically strong
C. Both (A) and (B)
D. None of the above

Copper oxide rectifier is usually designed not to operate above___________?

A. 20°C
B. 10°C
C. 30°C
D. 45°C

Ageing of a selenium rectifier may change the output voltage by__________?

A. 5 to 10 per cent
B. 25 to 30 per cent
C. 15 to 20 per cent
D. none of the above

The efficiency of the copper oxide rectifier seldom exceeds____________?

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

Selenium rectifier can be operated at temperatures as high as____________?

A. 40°C
B. 25°C
C. 60°C
D. 75°C

The applications of selenium rectifiers are usually limited to potential of_____________?

A. 30 V
B. 10 V
C. 60 V
D. 100 V
E. 200 V

In selenium rectifiers efficiencies ranging from _______ to _______ percent are attainable?

A. 40, 50
B. 25, 35
C. 60, 70
D. 75, 85

A commutating rectifier consists of commutator driven by___________?

A. a D.C. series motor
B. a synchronous motor
C. an induction motor
D. a D.C. shunt motor

In a mercury arc rectifier, the anode is usually made of_____________?

A. aluminium
B. copper
C. silver
D. graphite
E. tungsten

Which of the following rectifiers have been used extensively in supplying direct current for electroplating ?

A. Mercury arc rectifiers
B. Selenium rectifiers
C. Copper oxide rectifiers
D. Mechanical rectifiers
E. None of the above

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

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

Which of the following rectifiers are primarily used for charging of low voltage batteries from AC supply ?

A. Copper oxide rectifiers
B. Mechanical rectifiers
C. Selenium rectifiers
D. Electrolytic rectifiers
E. Mercury arc rectifiers

The efficiency of an electrolytic rectifier is nearly____________?

A. 70%
B. 80%
C. 60%
D. 40%

The ignited or auxiliary anode in mercury arc rectifier is made of____________?

A. aluminium
B. boron carbide
C. graphite
D. copper

Rectifiers And Converters Mcqs – (Electrical Engineering) MCQs Latest For FPSC, PPSC, NTS, KPPSC, SPSC & Other Tests

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