302. When a thyristor is conducting, the voltage drop across it is about
303. The use of free wheeling diode in controlled rectifier improves the waveshape of load current.
304. As the firing of a thyristor is delayed, the output voltage of a controlled rectifier decreases.
305. 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.
306. In a half bridge inverter circuit fed by a battery of voltage V, the rms value of fundamental component of output voltage is
307. In a full bridge single phase inverter feeding RLC load
308. It is possible to use a freewheeling diode in
309. 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.
310. 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
311. The factor η for a UJT is about
312. In a single phase full converter fed by a source having inductance, the number of thyristors conducting during overlap is
313. The cut in voltages for germanium and silicon diodes respectively as
314. 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
315. The output wave of a cycloconverter consists of a number of segments derived from the input wave.
316. 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
317. In a parallel inverter the turn off time tq of thyristor and values of commutating elements L and C are related as
318. A TRIAC can be turned on :
319. Which of the following devices has two gates?
320. In auxiliary commutated chopper, the peak value of thyristor current is
321. The ‘Contra rebels’ belong to?
322. The static equalisation circuit for thyristors connected in series is
323. A cycloconverter is a group of controlled rectifiers.
324. A single phase full wave regulator feeds a resistive load. The firing angle of thyristors is 90°. The input power factor is