Quiz

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Year 2024

July
Week # 4 Quiz 1

Q1. A necessary condition for a weighted code to be self-complementing is that the sum of its weights must be equal to

Q2. 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 ________.

Q3. A dc voltage source of 200 V is supplying R-L load through an SCR with pulse width of \(150 \mu s\). Compute the latching current of SCR in case load consists of R = 50 \(\Omega\) in series with L = 0.5 H.

Q4. In a series circuit which includes \(R = 2.4\: \Omega ,\: L = 25\: \mu H\), capacitor C and a thyristor for obtaining self commutation in the circuit, the value of capacitor should be

Q5. A single phase full wave AC voltage controller has a resistive load of 10 Ω and the input voltage is 230 V, 50 Hz. The delay angle of both the thyristors are \(45^\circ\). The input power factor is

Q6. A step up chopper is used to feed a load at 400 V DC from a 250 V DC source. The inductor current is continuous. If the ‘OFF’ time of the switch is 20 \(\mu s\), the switching frequency of the chopper in kHz is                

Q7. Resonant convertors are basically used to

Q8. A six pulse thyristor rectifier bridge is connected to a balanced 50 Hz three phase ac source. Assuming that the DC output current of the rectifier is constant. The lowest frequency harmonics component of the ac source line current is

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

Q10. In the buck-boost converter, what is the maximum value of switch utilization factor?