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The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier.

  • Pages : 1
  • Category : Electronics Engineering
    Category : Power Electronics
  • The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier.
    Table-Of-Content of This Book is awaiting to upload

    To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use

  • Pages : 1
  • Category : Electronics Engineering
    Category : Power Electronics
  • To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use
    Table-Of-Content of This Book is awaiting to upload

    In a full bridge circuit supplying an RLC under damped circuit

    • A. the waveshapes of output voltage and load current are square
    • B. the waveshapes of output voltage and load current are sinusoidal
    • C. the waveshapes of output voltage is square but the waveshape of load current is nearly sinusoidal
    • D. none of the above
    • Correct Answer: Option C

    In a dual converter operated in circulating current mode, the circulating current flows

    • A. when load current is zero
    • B. when load current is non-zero
    • C. even when load current is zero
    • D. none of the above
    • Correct Answer: Option C

    Assertion (A): Thyristors can be used in controlled heating, excitation systems of alternators, speed control of motors and HVDC Reason (R): A static var system using thyristors is very commonly used in high voltage ac systems.

    • A. Both A and R are correct and R is correct explanation of A
    • B. Both A and R correct but R is not correct explanation of A
    • C. A is correct but R is wrong
    • D. A is wrong but R is correct B
    • Correct Answer: Option B

    Thyristors can be used for control of

    • A. dc separately excited motor
    • B. dc shunt motor
    • C. dc series motor
    • D. all of the above
    • Correct Answer: Option D

    In a single phase cycloconverter with centre tapped transformer

    • A. all thyristors carry currents for equal duration
    • B. the durations of currents in all thyristors may or may not be equal
    • C. the durations of currents in all thyristors cannot be equal
    • D. the duration of currents in all thyristors must be equal for satisfactory operation
    • Correct Answer: Option B

    From which instant is the turn off time of a thyristor defined

    • A. when anode voltage becomes zero
    • B. when anode current becomes zero
    • C. when both anode voltage and current become zero
    • D. none of the above
    • Correct Answer: Option B

    As compared to a p-n junction diode

    • A. a schottky diode has lower cut in voltage and lower reverse saturation current
    • B. a schottky diode has higher cut in voltage and higher reverse saturation current
    • C. a Schottky diode has lower cut in voltage and higher reverse saturation current
    • D. a schottky diode has higher cut in voltage and lower reverse saturation current
    • Correct Answer: Option C

    In disc mounting of SCR

    • A. SCR is clamped on one side of disc shaped heat sink
    • B. SCR is clamped between two disc shaped heat sinks
    • C. The SCR has low current rating
    • D. None of the above
    • Correct Answer: Option B