Power Electronics Questions

• A dc chopper feeds an RLE load and has a duty cycle of 1. The load current will be such that
• A dc chopper is feeding an RLE load. The current can become discontinuous if
• In a cycloconverter it is possible to vary
• A single phase full bridge inverter for R-L loads needs
• In a full bridge inverter fed by a battery of voltage V, the rms value of fundamental component of output voltage is
• In a single phase full wave regulator feeding R-L load, short gate pulse are not suitable.
• Assertion (A): McMurray Bredford half bridge inverter uses complementary commutation Reason (R): Three phase inverter can have two modes of operation.
• A single phase semiconverter is supplying RLE load and has a freewheeling diode across the load. The firing angle is a. The freewheeling diode conducts for
• Which chopper circuit uses saturable reactor?
• For an illumination control circuit it is advisable to use a matched TRIAC-DIAC pair.
• In a series inverter
• When a UJT is used as a relaxation oscillator the current should be
• Two single phase semi-converters are connected in series to form a series converter. The input is v = Vm sin ωt and a1, a2 are the firing angles. If a1 = 0, the dc output voltage is
• If we connect two silicon unilateral switches in anti- parallel we get
• When UJT is used for thyristor gate signal, the output of UJT is
• In a single phase full wave regulator feeding a resistive load, the average current over one full cycle
• A UJT exhibits negative resistance characteristics when
• A 3 phase induction motor is controlled by voltage and frequency control such that the ratio V/f is constant. At 50 Hz, the starting torque is 100 N-m. At 25 Hz, the starting torque
• In a single phase semi-converter the number of thyristors is
• A NAND gate has 3 inputs and one output. The number of thyristors required for this gate are