logo

CuriousTab

CuriousTab

Discussion


Home Electronics and Communication Engineering Power Electronics Comments

  • Question
  • A chopper cannot be line commutated.


  • Options
  • A. True
  • B. False

  • Correct Answer
  • True 


  • Power Electronics problems


    Search Results


    • 1. Which converter is used in HVDC transmission?

    • Options
    • A. 3 pulse
    • B. 6 pulse
    • C. 12 pulse
    • D. 24 pulse
    • Discuss
    • 2. Which chopper circuit operates in all the 4 quadrants?

    • Options
    • A. A
    • B. C
    • C. D
    • D. E
    • Discuss
    • 3. The gate lead, in a thyristor is welded to :

    • Options
    • A. p layer to which anode is connected
    • B. n layer nearest to the anode terminal
    • C. p layer nearest to the cathode terminal
    • D. outside n layer
    • Discuss
    • 4. Natural commutation can be used in :

    • Options
    • A. DC circuits only
    • B. AC circuits only
    • C. both AC and DC circuits
    • D. none of the above
    • Discuss
    • 5. Which of the following devices exhibit negative resistance characteristics?

    • Options
    • A. UJT
    • B. PUT
    • C. Both UJT and PUT
    • D. UJT, PUT and SBS
    • Discuss
    • 6. Assertion (A): Typical value of thermal resistance from source to sink of an SCR is about 0.3° C/W

      Reason (R): Heat sinks of thyristors are generally made of aluminium.


    • 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
    • 7. In integral cycle control of ac regulators, the period of integral cycle control, i.e., (m + n) T should be

    • Options
    • A. less than mechanical or thermal time constant of the system
    • B. more than the mechanical or thermal time constant of the system
    • C. more or less than the mechanical or thermal time constant
    • D. very high
    • Discuss
    • 8. In load commutated chopper, the commutating element

    • Options
    • A. is capacitor
    • B. is capacitor and inductor
    • C. is capacitor, inductor and auxiliary thyristor
    • D. any of the above depending on load
    • Discuss
    • 9. Assertion (A): A transistor has lower voltage drop during conduction as compared to thyristor

      Reason (R): Transistors are manufactured in very high voltage and current ratings.


    • 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
    • 10. The symbol in figure is for

    • Options
    • A. SUS
    • B. SBS
    • C. SCS
    • D. None of the above
    • Discuss


    Comments

    There are no comments.

Enter a new Comment