Power Electronics Lab

In case of Class A commutation having ‘R’ as load

• L is connected in shunt with R

• L-C is connected in shunt with R

• L is connected in series with R

• L-C is connected in series with R

 Input to the single phase half controlled converter is Vmsinωt. If thyristor is triggered at an angle of 'α' equal to zero degree  , maximum value of the average output voltage would be

• Vm

• Vm/ $\pi$   
   

• 2Vm/  $\pi$  

• Vm/ α

Which of the following switching device is used in half controlled converter experiment ?

• MOSFET

• BJT

• GTO

• SCR

What will happen to the output if firing angle in an SCR is increased ?

• Increases

• Decreases

• Remains unchanged

• Maximum

In UJT firing circuit, pulses are generated when

• Capacitor discharges

• Capacitor charges

• Capacitor voltage is zero

• None of the above

A TRAIC is equivalent to

• a pair of anti-parallel SCRs

• a pair of parallel SCRs

• a pair of anti-series SCRs

• a pair of series SCRs

The typical value of “intrinsic stand ratio” of UJT is

• 0.1 to 0.4

• 0.5 to 0.85

• 0.85 only

• greater than 1

Jones chopper employs,

• Class D Commutation

• Class C Commutation

• Class B Commutation

• Class A Commutation

Which commutation technique is applied in parallel inverter?

• Current commutation

• Voltage commutation

• Load commutation

• External Commutation

As compared to SCR, the TRAIC has

• Low voltage and current rating

• High voltage and current rating

• Low voltage and high current rating

• High voltage and low current rating