MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Power Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Find the value of R in case of an RC firing circuit which is to be turned on with a source voltage of 150 V and the following parameters.Igt = 2AVd = 1.5VVgt = 125 V |
| A. | 11.75 Ω |
| B. | 54.25 Ω |
| C. | 96 Ω |
| D. | 5 Ω |
| Answer» B. 54.25 Ω | |
| 2. |
The figure shown below is that of an RC firing circuit.In case of negative cycle at Vs, the capacitor C |
| A. | charges through D2 with lower plate negative |
| B. | charges through D1 with lower plate negative |
| C. | charges through D2 with lower plate positive |
| D. | charges through D1 with lower plate positive |
| Answer» D. charges through D1 with lower plate positive | |
| 3. |
The figure shown below is that of a |
| A. | R firing circuit |
| B. | RC half-wave firing circuit |
| C. | RC full-wave firing circuit |
| D. | UJT triggering circuit |
| Answer» C. RC full-wave firing circuit | |
| 4. |
In case of a R firing circuit with Vgp > Vgt |
| A. | α = 90° |
| B. | α > 90° |
| C. | α < 90° |
| D. | α = 0° |
| Answer» D. α = 0° | |
| 5. |
In case of a R firing with R2 as the variable resistance, Vgp (peak of gate voltage) and Vgt (gate triggering voltage) the value of R2 is so adjusted such that |
| A. | Vgp = Vgt |
| B. | Vgp > Vgt |
| C. | Vgp < Vgt |
| D. | Vgp = Vgt = 0 |
| E. | and Vgt (gate triggering voltage) the value of R2 is so adjusted such thata) Vgp = Vgtb) Vgp > Vgtc) Vgp < Vgtd) Vgp = Vgt = 0 |
| Answer» B. Vgp > Vgt | |
| 6. |
In the figure given below, the resistance R1 is used to |
| A. | keep the gate circuit voltage drop minimum |
| B. | limit the gate current to a safe value when R2 = 0 |
| C. | limit the gate current to a safe value when R2 is very large |
| D. | allow the gate power dissipation |
| Answer» C. limit the gate current to a safe value when R2 is very large | |
| 7. |
In case of an RC half wave triggering circuit, the firing angle can be ideally varied between |
| A. | 0 to 180 |
| B. | 0 to 90 |
| C. | 0 to 120 |
| D. | 0 to 360 |
| Answer» B. 0 to 90 | |
| 8. |
The diode in the R firing circuit |
| A. | ensures that the gate voltage is a half wave DC pulse |
| B. | ensures that the gate voltage is a full wave DC pulse |
| C. | ensures that the gate voltage is a half wave AC pulse |
| D. | ensures that the gate voltage is a full wave AC pulse |
| Answer» C. ensures that the gate voltage is a half wave AC pulse | |
| 9. |
For a R firing circuit, the maximum value of source voltage is 100 V. Find the resistance to be inserted to limit the gate current to 2 A. |
| A. | 5 Ω |
| B. | 50 Ω |
| C. | 500 Ω |
| D. | 0.5 Ω |
| Answer» C. 500 Ω | |
| 10. |
In a resistance firing circuit the firing angle |
| A. | cannot be greater than 120° |
| B. | cannot be greater than 90° |
| C. | cannot be greater than 180° |
| D. | cannot be greater than 160° |
| Answer» C. cannot be greater than 180° | |