electrical engineering MCQs – Page 244

Practise multiple-choice questions from electrical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

electrical engineering Mcqs
1. economics of power generation2. analog electronics3. solid state switching circuits4. parallel circuits5. switchgear and protection6. op amp circuits7. transistor audio power amplifiers8. electrostatics9. heating and welding10. multi stage transistor amplifiers11. passive filters12. network theorems13. regulated d c power supply14. a c fundamentals circuits and circuit theory15. electromagnetic induction16. power electronics17. magnetism and electromagnetism18. transformers19. modulation and demodulation20. d c generators21. semiconductor theory22. single phase induction motors23. semiconductor diode24. hybrid parameters25. digital electronics26. oscillators27. earthing or grounding28. single stage transistor amplifiers29. d c motors30. transistor biasing31. amplifiers with negative feedback32. basic electrical33. electronic instruments34. synchronous motors35. field effect transistors fet36. magnetic circuit37. control systems38. industrial drives39. power generation40. series parallel circuits41. transistor tuned amplifiers42. electrical engineering materials43. rectifiers and converters44. integrated circuits45. scr silicon controlled rectifiers46. cables47. polyphase induction motors48. measurement and instrumentation49. transistors50. electrical machine design51. electrolysis and storage of batteries52. electric traction53. transmission and distribution
4861. DIAC are specifically designed to trigger______________?
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A. SCR

B. TRIAC

C. GTO

D. Only (a) and (b)
4862. The curve between V and I of SCR when anode is positive w.r.t cathode and when anode is negative w.r.t cathode are known as_____________________?
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A. both as forward characteristics

B. both as reverse characteristics

C. former as forward characteristics and later as reverse characteristics

D. former as reverse characteristics and later as forward characteristics

4863. The on state voltage drop of IGBT consists of__________?
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A. Drop across the drift region

B. Drop across MOSFET portion

C. All of these

D. Drop across the collector junction

4864. The output power of the cascaded amplifier / attenuator system can be determined using___________?
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A. Actual gain of amplifier

B. Actual gain of attenuator

C. Gain in dB of amplifier and attenuator

D. Actual gain of amplifier and attenuator
4865. Power transistor are type of___________?
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A. B.JTs

B. All of above

C. IGBTs

D. MOSFETs

4866. A single phase full bridge inverter can operate in load commutation mode in case load consists of____________?
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A. RLC overdamped.

B. RLC critically damped.

C. RL.

D. RLC underdamped.
4867. Which of following devices has highest di/dt and dv/dt capability?
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A. SITH

B. SCR

C. SIT

D. GTO
4868. The effects of EMI can be reduced by____________?
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A. All of these

B. Reducing the susceptibility of the receptor

C. Reducing the efficiency of the coupling path

D. Suppressing emissions

4869. The phase angle of gate signal in TRIAC can be shifted by using_____________?
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A. A variable resistor

B. An inductor

C. Only (a) and (b)

D. A capacitor

4870. To detect an over current fault condition, the most reliable method is to connect a_____________?
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A. Voltage sensor across IGBT

B. Current sensor in series with IGBT

C. Current sensor across IGBT

D. Voltage sensor in series with IGBT

4871. In square wave operation mode of 3 phase VSI, the VSI
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A. Can control the load voltage

B. Cannot control the load voltage except by means of dc link voltage

C. Cannot control the load voltage except by means of dc link current

D. Cannot control the load voltage

4872. If the anode current is 800 A, then the amount of current required to turn off the GTO is about____________?
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A. 200 A

B. 400 A

C. 600 A

D. 20 A

4873. During reverse recovery time__________________?
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A. charge carrier of junction J2 recombined

B. charge carrier of junction J1 is swept out

C. charge carrier of junction J3 is swept out

D. both B and C
4874. Maximum di / dt in a SCR is________?
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A. Directly proportional to Vm of supply voltage

B. Inversely proportional to Vm of supply voltage

C. Inversely proportional to L in the circuit

D. Both A and C

4875. A step down choppers can be used in___________?
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A. All of these

B. Electric traction

C. Electric vehicles

D. Machine tools

4876. Which following is a two terminal three layer device?
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A. BJT

B. MOSFET

C. None of above

D. Power dioed

4877. The main objective of static power converters is to____________?
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A. Obtain an ac output waveform from a dc power supply

B. Obtain an ac output waveform from a ac power suppl

C. Obtain an dc output waveform from a dc power supply

D. Obtain an dc output waveform from a dc power supply

4878. A full wave rectifier with resistive load produces___________?
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A. Do not produce harmonics

B. Fifth harmonic

C. Second harmonic

D. Third harmonic

4879. Electrical power output in a d.c. generator is equal to____________?
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A. Electrical power developed in armature iron and copper losses

B. Mechanical power input iron and friction losses

C. Mechanical power input iron and friction losses copper losses

D. Electrical power developed in armature copper losses

4880. What happen due to high di / dt____________?
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A. None of these

B. Insulation failure

C. Breakdown of junction

D. Local hot spot