64602. In a single phase full wave regulator feeding R-L load, short gate pulse are not suitable.
64603. Half bridge and full bridge inverters of one type use different commutation methods.
64604. In rectifier circuits, the rms value of ac component of output voltage is equal to
64605. A UJT exhibits negative resistance characteristics when
64606. A dc chopper feeds an RLE load and has a duty cycle of 1. The load current will be such that
64607. In rectifier circuits, ripple factor RF and form factor FF are related as
64608. If we connect two silicon unilateral switches in anti- parallel we get
64609. Assertion (A): SUS is a PUT and avalanche diode connected between gate and cathodeReason (R): SBS has two SUS inbuilt together and connected in anti-parallel
64610. In a single phase full wave controlled rectifier using centre tap transformer, the voltage across each half of secondary is Vm sin ωt. The peak inverse voltage is
64611. Which statement is correct?
64612. In a three phase series inverter, the firing frequency is
64613. A 3 phase fully controlled converter is a
64614. In a half bridge inverter the gate pulses of the two thyristors have a phase displacement of
64615. A fully controlled bridge converter can operate in quadrants
64616. A class E chopper
64617. A cycloconverter uses
64618. Assertion (A): A fully controlled bridge converter can operate in first and fourth quadrant.Reason (R): A semi converter is cheaper than a full converter.
64619. The commutation method in an inverter, is
64620. Inverters find applications in
64621. When a thyristor is conducting, the voltage drop across it is about
64622. The use of free wheeling diode in controlled rectifier improves the waveshape of load current.
64623. As the firing of a thyristor is delayed, the output voltage of a controlled rectifier decreases.
64624. Assertion (A): A GTO can be turned on and turned off by gate pulses Reason (R): A GTO can be turned off by negative gate pulse.
64625. In a half bridge inverter circuit fed by a battery of voltage V, the rms value of fundamental component of output voltage is
64626. In a full bridge single phase inverter feeding RLC load
64627. It is possible to use a freewheeling diode in
64628. Assertion (A): When the anode current of an SCR starts increasing during turn on process, the anode cathode voltage drop starts decreasing. Reason (R): During turn on the reverse biased junction in SCR breaksdown.
64629. In a certain inverter circuit each thyristor carries 26.67 A for 60°, 13.33 A for 120° and zero A for 180° of the cycle. The rms current of thyristor is
64630. The factor η for a UJT is about
64631. The storage capacity of a oxygen cylinder is:
64632. In a single phase full converter fed by a source having inductance, the number of thyristors conducting during overlap is
64633. The cut in voltages for germanium and silicon diodes respectively as
64634. An SCR is triggered at 80° in the positive half cycle, only. The rms anode current is 25 A. If the firing angle is changed to 160°, the rms current is likely to be
64635. The output wave of a cycloconverter consists of a number of segments derived from the input wave.
64636. A class A chopper has an input voltage of 200 V. Ton = 1.5 ms and Toff = 4.5 ms. The duty cycle, average output voltage and ripple factor respectively are
64637. In a parallel inverter the turn off time tq of thyristor and values of commutating elements L and C are related as
64638. A TRIAC can be turned on :
64639. Which of the following devices has two gates?
64640. In auxiliary commutated chopper, the peak value of thyristor current is
64641. What is the range of flame temperature of oxygen-hydrogen gases?
64642. The ‘Contra rebels’ belong to?
64643. The static equalisation circuit for thyristors connected in series is
64644. A cycloconverter is a group of controlled rectifiers.
64645. A single phase full wave regulator feeds a resistive load. The firing angle of thyristors is 90°. The input power factor is
64646. The leads in a TRIAC are denoted by
64647. A step down cycloconverter has an input frequency f. If it uses natural commutation, the output frequency
64648. In a single phase full wave regulator, the rms current in each thyristors is Ir The run load current is equal to