The main objective of static power converters is to____________?

Related Mcqs:

1. In the operation and control of both naturally commutated and forced commutated SCR base converter, commutation plays an important role. The converters is / are ___________?

   A. AC – DC
   B. DC – DC
   C. DC – AC
   D. All of these

2. The output current in PWM DC – DC converters is equal to___________?

   A. Average value of the output inductor current
   B. Product of an average inductor current and a function of duty ratio
   C. Either A. or B.
   D. None of these

3. A power semiconductor may undergo damage due to____________?

   A. High di/dt
   B. High dv/dt
   C. Low di/dt
   D. Low dv/dt

4. Electrical power output in a d.c. generator is equal to____________?

   A. Electrical power developed in armature – copper losses
   B. Mechanical power input – iron and friction losses
   C. Electrical power developed in armature – iron and copper losses
   D. Mechanical power input – iron and friction losses – copper losses

5. In a full wave rectifier, the rectification ratio is approximately equal to____________?

   A. 61%
   B. 71%
   C. 81%
   D. 91%

6. Power electronics essentially deals with control of a.c. power at____________?

   A. Frequencies above 20 kHz
   B. Frequencies above 1000 kHz
   C. Frequencies less than 10 Hz
   D. 50 Hz frequency

7. Practical way of obtaining static voltage equalization in series connected SCRs is by the use of____________?

   A. One resistor across the string
   B. Resistors of the same value across each SCR
   C. Resistors of different values across each SCR
   D. One resistor in series with each SCR

8. For an SCR gate – cathode characteristic is a straight line of 130. For triggered source volume of 15 V and allowable gate power dissipation of 0.5 W compute the gate source resistance_____?

   A. 111.9 Ω.
   B. 11.19 Ω.
   C. 108 Ω.
   D. 115 Ω

9. Compared to transistor, _________ have lower on state conduction losses and higher power handling capability?

   A. TRIACs
   B. Semi conductor diodes
   C. MOSFETs
   D. Thyristor

10. The power demand can be estimated approximately by____________?

    A. Load survey method
    B. Mathematical method
    C. Statistical method
    D. Economic parameters