Power Electronics Questions

• Surge current rating of an SCR is
• A surge voltage
• The total number of leads in SUS, SBS and SCS respectively are
• A bridge type single phase cycloconverter changes the frequency f to f/3. Then one half wave of output contains
• The turn on characteristics of a power transistor can be assumed to be linear, as shown in the below figure . During turn on time T, voltage reduces linearly from V to 0 and current rises linearly from 0 to I. The energy loss during time T is
• The circuit in figure is for
• Typical values of for an SCR are in the range of
• A dc chopper is feeding an RLE load. The condition for maximum ripple is
• Assertion (A): A DIAC has four layers but only two terminals. Reason (R): A DIAC can conduct in both directions.
• A step up chopper can give an output voltage
• In a single phase full wave ac regulator the firing angles during both half cycles are equal.
• A string of series connected thyristors needs equalising circuit to
• Multiphase choppers are used in
• In a 3 phase full converter feeding a highly inductive load, the average load current is 150 A. The peak current through thyristor is
• A half bridge inverter
• A 3 phase series inverter has
• In a single phase converter using a centre tapped transformer and with a highly inductive load, the firing angles is a. Each thyristor conducts for a period
• The symbol in figure is for
• In a single phase half wave converter feeding resistive load and full wave converter (M - 2 connection) feeding a resistive load the circuit conditions are similar. The firing angle is a. Then the waveshapes of voltages across thyristors
• HVDC systems are preferable for only long distances.