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  • Question
  • The phenomenon of overlap in converter operation due to


  • Options
  • A. source resistance
  • B. source inductance
  • C. both source resistance and source inductance
  • D. high value of firing angle

  • Correct Answer
  • source inductance 

    Explanation
    Source inductance delays turn off and hence causes overlap.

    Power Electronics problems


    Search Results


    • 1. Assertion (A): A transistor requires a continuous base signal for conduction but a thyristor requires a gate pulse.

      Reason (R): Transistor find widespread application in power electronic circuits.


    • Options
    • 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
    • Discuss
    • 2. Current derating may be necessary when thyristors are operating in

    • Options
    • A. series
    • B. parallel
    • C. series or parallel
    • D. none of the above
    • Discuss
    • 3. The total number of leads in reverse conducting thyristor is

    • Options
    • A. 2
    • B. 3
    • C. 1
    • D. 4
    • Discuss
    • 4. If Vdc1 is the dc output voltage in half wave controlled rectifier circuit feeding resistive load and Vdc2 is the dc output voltage in full wave controlled rectifier circuit (M - 2 connection) feeding resistive load, then

    • Options
    • A. Vdc1 = 0.5 Vdc2 for all values of firing angle
    • B. Vdc1 = Vdc2 for all values of firing angle
    • C. Vdc1 ? 0.5 Vdc2 for all values of firing angle
    • D. Vdc1 ? 0.5 Vdc2 for all values of firing angle
    • Discuss
    • 5. In a circuit using a full wave converter (M - 2 connection) the PIV of each thyristor is 400 V. For the same output voltage and fully controlled bridge converter, PIV will be

    • Options
    • A. 400 V
    • B. 800 V
    • C. 200 V
    • D. 2002 V
    • Discuss
    • 6. A single phase semiconverter is feeding a highly inductive load and has freewheeling diode across the load. The waveshapes of output voltage and output current

    • Options
    • A. are similar
    • B. are not similar
    • C. may be similar or dissimilar
    • D. are similar only if firing angle is zero
    • Discuss
    • 7. A semiconverter feeding an RLE load operates in

    • Options
    • A. first quadrant only
    • B. first and second quadrants
    • C. first and fourth quadrants
    • D. first and third quadrants
    • Discuss
    • 8. Assertion (A): Inverters and choppers use fast switching thyristors

      Reason (R): Fast switching SCR has low turn off time.


    • Options
    • 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
    • Discuss
    • 9. For a BJT a = 0.98, then ? =

    • Options
    • A. 0.02
    • B. 0.5
    • C. 4.9
    • D. 48
    • Discuss
    • 10. The terminals of a power BJT are called

    • Options
    • A. emitter, base, collector
    • B. emitter, base, drain
    • C. source, base, drain
    • D. source, base, collector
    • Discuss


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