Quiz

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Year 2024

January
Week # 4 Quiz 1

Q1. The percentage resolution of 6 bit Digital to Analog convertor would be

Q2. 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.

Q3. 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>

Q4. A single-phase full-bridge voltage source inverter (VSI) is fed from a 300 V battery. A pulse of 120° duration is used to trigger the appropriate devices in each half-cycle. The rms value of the fundamental component of the output voltage, in volts, 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 a firing angle of 60°, assuming continuous conduction?

Q6. For an SCR gate cathode characteristic is a straight line of 110 and allowable gate power dissipation is 0.5 W. Compute the gate current.

Q7. What is the maximum firing angle achievable using resistance-capacitance triggering of SCR?

Q8. A single-phase full-wave uncontrolled bridge rectifier is supplying a highly inductive load (L/R ratio is very large), the load current is assumed to be smooth and ripple –free. If the supply voltage is 230V, 50Hz, and the inductor load resistance R = 20 \(\Omega\), Calculate the average output voltage.

Q9. Identify the expression:
\(\frac{V_{max}}{2\pi R_L}(1+cos\alpha)\)

Q10. In a 12 pulse valve group operation the most troublesome harmonics on ac side are