logo

CuriousTab

CuriousTab

Discussion


Home Electronics and Communication Engineering Power Electronics Comments

  • Question
  • A single phase semiconverter is feeding a highly inductive load and has a freewheeling diode across the load. The waveshape of input current is


  • Options
  • A. sinusoidal
  • B. rectangular
  • C. sinusoidal or rectangular
  • D. triangular

  • Correct Answer
  • rectangular 


  • Power Electronics problems


    Search Results


    • 1. In the below figure, the load is highly inductive. The firing angle is a for each of the thyristors. The periods of conduction of Th1 and Th2 respectively are

    • Options
    • A. 0 to p and p to 2p
    • B. a to p and p + a to 2p
    • C. a to p + a and p + p to 2p + a
    • D. a to p - a and p + a to 2p - a
    • Discuss
    • 2. A rectifier is fed by a transformer. The rms voltage and current at secondary of transformer are Vs and Is. Output dc power is Vdc Idc and output ac power is (Vrms ) (Irms), Transformer utilisation factor TUF is

    • Options
    • A.
    • B.
    • C.
    • D.
    • Discuss
    • 3. A single phase full wave regulator feeds a resistive load. The firing angle of thyristors is 90°. The input power factor is

    • Options
    • A. 1
    • B. 0.707 lagging
    • C. 0.5 lagging
    • D. 0.2 lagging
    • Discuss
    • 4. In a parallel inverter the turn off time tq of thyristor and values of commutating elements L and C are related as

    • Options
    • A. tq = pLC
    • B. tq = LC
    • C. tq = LC
    • D. tq = LC
    • Discuss
    • 5. In a full bridge single phase inverter feeding RLC load

    • Options
    • A. one thyristor and one diode conduct simultaneously
    • B. two thyristors conduct simultaneously
    • C. two thyristors or two diodes conduct simultaneously
    • D. four thyristors conduct simultaneously
    • Discuss
    • 6. A crowbar circuit is generally needed for protection under fault conditions.

    • Options
    • A. True
    • B. False
    • Discuss
    • 7. A single phase fully controlled bridge converter is fed by a voltage Vm sin ?t. The average and rms values of output voltage are

    • Options
    • A.
    • B.
    • C. cos a and Vm
    • D. cos a and 2 Vm
    • Discuss
    • 8. In a bridge inverter

    • Options
    • A. an output transformer is essential
    • B. an output transformer is not essential
    • C. an output transformer cannot be connected
    • D. an output transformer, if used, can improve the efficiency of the circuit
    • Discuss
    • 9. In a modified series inverter with two inductors and two capacitors, the load current

    • Options
    • A. has 2 parallel paths
    • B. has only one parallel path
    • C. can have three parallel paths
    • D. has four parallel paths
    • Discuss
    • 10. The number of leads in a DIAC are

    • Options
    • A. 2
    • B. 3
    • C. 4
    • D. 6
    • Discuss


    Comments

    There are no comments.

Enter a new Comment