Year 2023

Week # 4 Quiz 1

Q1. When will be the output of an AND gate is HIGH if there are three inputs, A, B, and C ?

Q2. A 220 V DC supply is connected to a DC chopper which is operating on TRC control mode at a frequecy of 5 kHz. When the output is 110 V, the ON and OFF period of each cycle are respectively

Q3. If an SCR gate cathode characteristic is a straight line of 130 and allowable gate power dissipation of 0.7 W, then the gate voltage is ________.

Q4. A dc voltage source of is supplying R-L load through an SCR with pulse width of \(100 \mu s\). Latching current of SCR is 100 mA in case load consists of R = 20 \(\Omega\) in series with L = 0.5 H.

Q5. An SCR is triggered at 30° in the positive half cycle only. The average anode current is 40 A. If the firing angle is changed to 80°, the average anode current is likely to be

Q6. A single phase half wave rectifier is feeding a resistive load. When  \(\alpha = 0\), dc output voltage is 134 V. When \(\alpha = 45°\), the dc output voltage will be about

Q7. The peak inverse voltage in ac to dc converter system is highest in

Q8. The reverse recovery time of diode \(t_{rr} = 3.5 \:\mu s\) and the stored charge \(Q_{RR} = 122.5\:\mu C \). Calculate the rate of change of the diode current \(di/dt \).

Q9. In signal pulse modulation of PWM inverter,\(5^{th}\) harmonic can be eliminated if pulse width is equal to __________degree.

Q10. The scaling factor using MOS device using constant voltage scaling model, the gate area of the device will be scaled as