Power Electronics Questions

• Which of these commutation methods uses an auxiliary SCR?
• In an SCR, the anode current is controlled by
• A single phase half wave controlled rectifier circuit has an R-L load. A freewheeling diode is also in the circuit. When freewheeling diode is conducting the SCR
• A single phase semiconverter is feeding a highly inductive load. The circuit has a freewheeling diode across the load and firing angle is a. During one cycle of input voltage, the total duration of conduction of freewheeling diode is
• A DIAC has two terminals, anode and cathode.
• The rated current of a thyristor is 40 A. The holding current will be about :
• Induction heating systems require low frequency inverters.
• A static induction thyristor
• UJT can be used for
• A thyristor is reverse biased. A positive gate pulse is applied. The thyristor
• In a 3 phase full converter the average load current is 150 A. The average thyristor current is
• The number of leads in a power semiconductor diode are
• A dc chopper is feeding an RLE load. The maximum steady state ripple is
• In a 3 phase full wave regulator feeding resistance load connected in star, the possible range of firing angle a is
• In a single phase full wave converter (M - 2 connection), the rms transformer voltage is 300 V across each half of secondary. The PIV for each thyristor is
• In a single phase full wave regulator feeding R-L load, the minimum firing angle can be zero.
• A single phase half wave converter is feeding a resistive load. Just before triggering, the voltage across thyristor is
• Current chopping leads to
• A reactor is used in a dual converter operating in non-circulating current mode.
• Assertion (A): The gate current of an SCR is always in the form of pulses. Reason (R): The gate losses, in pulse triggering, are low.