Year 2024

Week # 4 Quiz 1

Q1. Which of the following shift register will require minimum number of clock pulses to give the output?

Q2. A single-phase thyristor-bridge rectifier is fed from a 230V, 50 Hz, single-phase, AC mains. If it is delivering a constant DC current of 10 A, at firing angle of 30°, then value of the power factor at AC mains is

Q3. Figure shows two thyristors rated 350 A sharing a load current. Current through \(T_2\) is 180A. Current through \(T_1\) will be _____ .

Q4. A thyristor has thermal resistance is 1.8 °C/W and the maximum allowable internal power dissipation is 50 W. If the ambient temperature is 40 °C, the maximum allowable Junction temperature is

Q5. The fully controlled thyristor converter in the figure is fed from a single phase source. When the firing angle is 0˚, the DC output voltage of the converter is 300 V. What will be the output voltage for firing angle of 60˚? (Assume continuous conduction) <br><br>

Q6. A boost converter operating at duty cycle of 0.5 with input voltage of 100 V dc suppling a resistive load of 100 \(\Omega\). The input current of the buck converter will be,

Q7. Identify the expression:
\(\frac{V_{max}}{2\pi R_L}(1+cos\alpha)\)

Q8. A half-controlled single-phase bridge rectifier is supplying an R-L load. It is operated at a firing angle \(\alpha\) and the load current is continuous. The fraction of cycle that the freewheeling diode conducts is

Q9. 5 thyristors rated 200 V in series. The operating voltage of the string is 900 V. Derating factor of the string is

Q10. A step down DC chopper has input voltage of 200 V with 10 Ω load resistor connected, voltage drop across chopper is 2 V when it is ON. For a duty cycle of 0.6, calculate the average value of output voltage.