logo

CuriousTab

CuriousTab

Discussion

Home ‣ Electronics and Communication Engineering ‣ Power Electronics See What Others Are Saying!
  • Question

  • A dc series motor is coupled to a load whose torque is proportional to speed. It is fed by a single phase ac supply through a full converter. When speed is 500 rpm, firing angle is 45°. It is desired to raise the speed. It will be necessary to


  • Options
  • A. decrease the firing angle
  • B. increase the firing angle
  • C. either decrease or increase the firing angle depending on the required speed
  • D. decrease the load torque

  • Correct Answer
  • decrease the firing angle 

    • More questions

    • 1. The symbol in figure is for

    • Options
    • A. UJT
    • B. PUT
    • C. SCS
    • D. SBS
      • Discuss
    • 2. Which of these devices can conduct in both directions?

    • Options
    • A. SCR
    • B. SUS
    • C. SBS
    • D. UJT
      • Discuss
    • 3. In the given figure forward current wave has a magnitude of

    • Options
    • A. 0.45 A
    • B. 0.3 A
    • C. 0.2 A
    • D. 0.1 A
      • Discuss
    • 4. A typical signal strength received from a geosynchronous communication satellite is of the order of a few

    • Options
    • A. milliwatts
    • B. kilowatts
    • C. picowatts
    • D. watts
      • Discuss
    • 5. The temperature at which some materials become superconductors is called

    • Options
    • A. Transition temperature
    • B. Curie temperature
    • C. Neel temperature
    • D. Onnes temperature
      • Discuss
    • 6. The advantage of modified series inverter with two inductors and two capacitors is

    • Options
    • A. the intermittent operation of battery is avoided
    • B. efficiency of circuit is more
    • C. the output frequency is low
    • D. all of the above
      • Discuss
    • 7. A chopper cannot be line commutated.

    • Options
    • A. True
    • B. False
      • Discuss
    • 8. Three point tracking can be achieved with

    • Options
    • A. gang condenser
    • B. variable selectivity
    • C. paddar capacitor
    • D. any of the above
      • Discuss
    • 9. In TE and TM modes of rectangular waveguides having propagation in z direction

    • Options
    • A. Ez and Hz are both zero
    • B. In TE mode Ez is zero and in TM mode Hz is zero
    • C. In TE mode Hz is zero and in TM mode Ez is zero
    • D. In both TE and TM modes both Ez and Hz are non-zero
      • Discuss
    • 10. Standard AM radio broadcasts are confined to

    • Options
    • A. MF
    • B. HF
    • C. VHF
    • D. UHF
      • Discuss

    Comments

    There are no comments.
Enter a new Comment




Aptitude

Engineering

Programming

Reasoning

Links

Copyright ©CuriousTab. All rights reserved.