An UJT, the p-type emitter is . . . . . . . . doped
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Power Electronics
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A single-phase full-wave AC phase controller feeds power to a resistive load of 100 Ω from a 220 V, 50 Hz supply. What will be the rms output voltage at delay angles of both transistors?
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Consider the following statements:
A four-layer PNPN device having two gate leads can turned on by applying a
1. positive current pulse to the cathode gate
2. positive current pulse to the anode gate
3. negative current pulse to the anode gate
4. negative current pulse to the cathode gate
Which of these statements is/are correct?
A four-layer PNPN device having two gate leads can turned on by applying a
1. positive current pulse to the cathode gate
2. positive current pulse to the anode gate
3. negative current pulse to the anode gate
4. negative current pulse to the cathode gate
Which of these statements is/are correct?
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A Silicon Controlled Resistor (SCR) is made up of silicon and not germanium because
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An a.c. regulator can be designed with
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The gate current required to turn on an SCR is
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A freewheeling diode in a phase controlled rectifier
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Consider the following statements: An SCR, from its OFF state, can be made ON by-
1. increasing its anode voltage
2. increasing its gate current
3. decreasing its gate voltage
4. decreasing its anode current
Which one of the following statements is correct?
1. increasing its anode voltage
2. increasing its gate current
3. decreasing its gate voltage
4. decreasing its anode current
Which one of the following statements is correct?
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Power diode are used with
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Match List-I with List-II and select the correct answer using the options given below:
| List-I (SCR Rating) | List-II (Protective element) |
| a. di/dt limit | 1. Snubber circuit |
| b. dv/dt limit | 2. Heat sink |
| c. i2t limit | 3. Series reactor |
| d. Junction temperature limit | 4. Fuse |
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How is the GTO turned off?
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A power diode has lightly doped n type substrate sandwiched between heavily doped p and n regions
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An SCR has an anode supply of sine voltage 200 Vr.m.s, 50 Hz applied through a 100 Ω resistor and fired at an angle of 60°. Assuming no voltage drop, the r.m.s. value of the output voltage is nearly
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In the forward blocking region of a silicon controlled rectifier, the SCR is
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An SCR is sometimes called . . . . . . . .
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Between the peak point and the valley point of UJT emitter characteristics we have . . . . . . . . region
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The electronic circuit that converts AC to DC where the DC output peak value can be greater than the AC input peak value is-
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A step down chopper is operated in the continuous conduction mode in steady state with constant duty ratio D. If Vo is the magnitude of the DC output voltage and if Vs is the magnitude of the DC input voltage, the ratio is given by
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In thyristor, holding current is
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Which one of the following can be used in the lighting system for power interruptions?
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