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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Calculate the output voltage of the Boost converter if the supply voltage is 1 V and duty cycle value is .9.(a) 10 V(b) 20 V(c) 40 V(d) 60 VI had been asked this question in final exam.The origin of the question is Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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| 2. |
Calculate the value of Crest factor if Vpeak=1.5 V and Vr.m.s=2.5 V.(a) .4(b) .6(c) .5(d) .7The question was posed to me in class test.This interesting question is from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct ANSWER is (b) .6 |
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| 3. |
Calculate the De-rating factor if the string efficiency is 90 %.(a) .4(b) .1(c) .7(d) .8I have been asked this question during an interview.This key question is from Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct OPTION is (a) .4 |
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| 4. |
A step-down chopper has input voltage 12 V and output voltage 2 V. Calculate the value of the duty cycle.(a) 0.26(b) 0.16(c) 0.33(d) 0.41I have been asked this question in unit test.My question comes from Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» Right answer is (b) 0.16 |
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| 5. |
____________ is the switching frequency of SITH.(a) 55 KHz(b) 100 KHz(c) 91 KHz(d) 105 KHzThis question was addressed to me in semester exam.This interesting question is from Solid-State Devices topic in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct option is (b) 100 KHz |
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| 6. |
Device with highest d(i)÷d(t) and d(v)÷d(t) capability is _____________(a) GTO(b) BJT(c) SCR(d) SITHI got this question by my school principal while I was bunking the class.The origin of the question is Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct CHOICE is (d) SITH |
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| 7. |
What is the formula for thermal voltage?(a) K×e÷T(b) K×T÷e(c) K^2×e÷T(d) K×e^2÷TI had been asked this question in homework.I want to ask this question from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct choice is (a) K×E÷T |
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| 8. |
SCR is unipolar.(a) True(b) FalseThe question was asked in examination.My query is from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» Right choice is (b) False |
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| 9. |
The most reliable method for thyristor triggering is thermal triggering.(a) True(b) FalseThis question was addressed to me during an interview.My doubt stems from Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» Right option is (b) FALSE |
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| 10. |
Calculate the string efficiency if the de-rating factor is .22.(a) 78 %(b) 42 %(c) 20 %(d) 90 %I have been asked this question in an internship interview.Enquiry is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» CORRECT option is (a) 78 % For EXPLANATION I would say: The string efficiency is calculated for SERIES and parallel CONNECTION of SCRs. The value of string efficiency is 1-(De-rating FACTOR)=1-.22=78 %. |
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| 11. |
25 V rated n SCRs are connected in series. The operation voltage of the string is 300 V and the string efficiency is 40 %. Calculate the value of n.(a) 27(b) 30(c) 34(d) 36This question was posed to me in an online quiz.The origin of the question is Solid-State Devices in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» Correct choice is (b) 30 |
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| 12. |
High d(v)÷d(t) causes _______________(a) Local hotspots(b) False triggering(c) High cost(d) High-speed operationI have been asked this question during an interview.My question is taken from Solid-State Devices topic in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The CORRECT answer is (b) FALSE triggering |
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| 13. |
Calculate the value of output r.m.s voltage for Single phase Full-bridge inverter if the DC supply is 25 V.(a) 26 V(b) 25 V(c) 27 V(d) 28 VI have been asked this question in an international level competition.This intriguing question originated from Solid-State Devices topic in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct option is (b) 25 V |
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| 14. |
High d(i)÷d(t) causes _______________(a) Local hotspots(b) Breakdown(c) High cost(d) Low costI got this question in an online interview.The question is from Solid-State Devices topic in section Introduction to Solid-State Devices of Electric Drives |
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Answer» Correct option is (a) Local hotspots |
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| 15. |
Calculate the value of output r.m.s voltage for Single phase Half-bridge inverter if the DC supply is 80 V.(a) 40 V(b) 20 V(c) 10 V(d) 60 VI had been asked this question during a job interview.My doubt stems from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» Right CHOICE is (a) 40 V |
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| 16. |
Third lowest order harmonic present in 3-Φ fully controlled rectifier is __________(a) 11^th(b) 17^th(c) 13^th(d) 22^ndI had been asked this question in final exam.Origin of the question is Solid-State Devices topic in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» RIGHT ANSWER is (a) 11^th Easy explanation: Only 6k±1 order harmonics are present in 3-Φ fully controlled RECTIFIER. The lowest order harmonic is 11^th harmonic for k=2. Third order harmonics are ABSENT in 3-Φ fully controlled rectifier. |
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| 17. |
Thyristors are used in parallel to complete ________(a) High voltage demand(b) High current demand(c) Low current demand(d) Low voltage demandThis question was posed to me by my school principal while I was bunking the class.This question is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct option is (C) LOW current demand |
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| 18. |
Which harmonic is not present in 3-Φ fully controlled rectifier?(a) 27^rd harmonic(b) 15^th harmonic(c) 17^th harmonic(d) 12^th harmonicThe question was posed to me in homework.I need to ask this question from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» Right option is (a) 27^rd harmonic |
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| 19. |
Calculate peak-peak voltage if Vmax=200 V and Vmin=190 V.(a) 20 V(b) 10 V(c) 60 V(d) 80 VI had been asked this question during an online exam.I need to ask this question from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» RIGHT answer is (b) 10 V For explanation I would say: Peak-Peak VOLTAGE is EQUAL to the DIFFERENCE between the maximum and minimum voltage. It is mathematically represented as Vp-p=Vmax-Vmin=200-190=10 V. |
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| 20. |
The range of On-State voltage drop is _______(a) 1-1.6 V(b) 0-1 V(c) 1.6-2 V(d) 2.4-3 VThis question was addressed to me during an online interview.Question is taken from Solid-State Devices topic in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct ANSWER is (a) 1-1.6 V |
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| 21. |
Thyristors are used in series to complete ________(a) High voltage demand(b) High current demand(c) Low voltage demand(d) Low current demandI got this question at a job interview.This is a very interesting question from Solid-State Devices topic in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct OPTION is (C) LOW voltage demand |
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| 22. |
The range of turn-off time is _______(a) .51-3 μsec(b) 3-101 μsec(c) 9-400 μsec(d) 7-787 μsecThis question was addressed to me by my college director while I was bunking the class.Query is from Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct answer is (b) 3-101 μsec |
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| 23. |
100 V rated 3 SCRs are connected in series. The operation voltage of the string is 200. Calculate the De-rating factor.(a) .35(b) .33(c) .38(d) .18This question was posed to me during an internship interview.My query is from Solid-State Devices in division Introduction to Solid-State Devices of Electric Drives |
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Answer» CORRECT option is (b) .33 The explanation: The string efficiency can be calculated using the FORMULA OPERATION VOLTAGE÷(Number of SCRs×Rated voltage) = 200÷(100×3) = .66. The De-rating FACTOR value is 1-.66 = .33. |
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| 24. |
Gate triggering is more reliable.(a) True(b) FalseThis question was addressed to me during an interview.This intriguing question originated from Solid-State Devices topic in section Introduction to Solid-State Devices of Electric Drives |
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Answer» RIGHT option is (a) True Explanation: Gate TRIGGERING is more reliable than any other triggering method. The RISK of false triggering of SCR REDUCES in the case of gate triggering. |
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| 25. |
Calculate the string efficiency if the de-rating factor is .48.(a) 48 %(b) 52 %(c) 50 %(d) 60 %This question was posed to me in an online interview.Question is taken from Solid-State Devices in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» Correct option is (B) 52 % |
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| 26. |
400 V rated 5 SCRs are connected in series. The operation voltage of the string is 500. Calculate the string efficiency.(a) 25 %(b) 40 %(c) 38 %(d) 35 %This question was posed to me during a job interview.The origin of the question is Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» RIGHT choice is (a) 25 % Best explanation: The string efficiency can be calculated using the formula OPERATION VOLTAGE÷(Number of SCRs×Rated voltage) = 500÷(400×5) = 25 %. |
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| 27. |
Calculate the De-rating factor if the string efficiency is 20 %.(a) .8(b) .4(c) .5(d) .6The question was posed to me in an interview.My question is taken from Solid-State Devices topic in section Introduction to Solid-State Devices of Electric Drives |
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Answer» RIGHT choice is (a) .8 To EXPLAIN: De-rating factor is used to MEASURE the reliability of a STRING. The value of the De-rating factor is 1-(string efficiency) = 1-.2 = .8. |
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| 28. |
A step-down chopper has input voltage 40 V and output voltage 20 V. Calculate the value of the duty cycle.(a) 0.5(b) 0.2(c) 0.3(d) 0.4I had been asked this question in an online interview.My query is from Solid-State Devices topic in section Introduction to Solid-State Devices of Electric Drives |
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Answer» CORRECT option is (a) 0.5 Easy explanation: The OUTPUT voltage of the STEP-down chopper is Vo = Vin×(D). The value of the duty cycle is less than ONE which makes the Vo < Vin. The step-down chopper is used to step down the voltage. The value of the duty cycle is 20÷40 = .5. |
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| 29. |
R-L-C overdamped loads are generally lagging power factor loads.(a) True(b) FalseI have been asked this question in an international level competition.Asked question is from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The CORRECT answer is (a) True |
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| 30. |
Which one of the following load is suitable for load commutation in Single phase Half-bridge inverter?(a) R-L load(b) R-L-C overdamped(c) R-L-C underdamped(d) L-loadI have been asked this question by my school teacher while I was bunking the class.Enquiry is from Solid-State Devices in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» Correct answer is (c) R-L-C underdamped |
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| 31. |
Calculate the value of Vpeak if crest factor=47 and Vr.m.s=6 V.(a) 282 V(b) 300 V(c) 290 V(d) 286 VThis question was posed to me in a national level competition.My doubt is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» Correct choice is (a) 282 V |
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| 32. |
When maximum power loss occurs?(a) Rise time(b) Delay time(c) Spread time(d) Rise time or Delay timeI have been asked this question in an online interview.My enquiry is from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct choice is (a) Rise time |
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| 33. |
A snubber circuit is used with thyristor in ____________(a) Parallel(b) Series(c) Anti-parallel(d) Series or ParallelI had been asked this question during an online exam.The origin of the question is Solid-State Devices topic in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The CORRECT choice is (a) Parallel |
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| 34. |
Which of the following is used to protect SCR from d(v)/d(t) condition?(a) Capacitor(b) Fuse(c) Snubber circuit(d) InductorI have been asked this question in exam.My doubt is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» CORRECT ANSWER is (c) Snubber circuit Easiest explanation: Snubber circuit is used to PROTECT SCR from d(v)/d(t) CONDITION. Snubber circuit consists of a Capacitor and resistor. The capacitor does not ALLOW the sudden change in voltage and resistor resists the discharging of the capacitor. |
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| 35. |
Which of the following is used to protect SCR from d(i)/d(t) condition?(a) Inductor(b) Capacitor(c) Heat sink(d) FuseThis question was posed to me during an interview.This interesting question is from Solid-State Devices in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct option is (a) Inductor |
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| 36. |
Which of the following is used to protect SCR from thermal conditions?(a) Heat sink(b) Voltage clamping device(c) Zener diode(d) Snubber circuitI have been asked this question in examination.My enquiry is from Solid-State Devices topic in section Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct ANSWER is (a) Heat sink |
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| 37. |
Which of the following is used to protect SCR from overcurrent?(a) Heat sink(b) Fuse(c) Snubber circuit(d) Zener diodeThe question was posed to me by my school principal while I was bunking the class.Enquiry is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct option is (B) Fuse |
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| 38. |
If latching current of an SCR is 10 mA then its holding current should be ____________(a) 5 mA(b) 7 mA(c) 8 mA(d) 4 mAI have been asked this question in my homework.My doubt is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct OPTION is (a) 5 mA |
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| 39. |
If holding current of an SCR is 6 mA then its latching current should be ___________(a) 4 mA(b) 5 mA(c) 12 mA(d) 6 mAI got this question during an online interview.This interesting question is from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» Right OPTION is (c) 12 mA |
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| 40. |
Holding current of the SCR is ___________(a) > than latching current(b) < than latching current(c) = to latching current(d) ≥ than latching currentThis question was posed to me in an international level competition.My question is taken from Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct choice is (B) < than LATCHING current |
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| 41. |
SCR is a__________ device.(a) Uncontrolled(b) Semi-controlled(c) Fully controlled(d) VoltageThis question was addressed to me in an interview for internship.I'd like to ask this question from Solid-State Devices topic in section Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct CHOICE is (b) Semi-controlled |
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| 42. |
For successful commutation circuit turn-off time ______ device turn-off time.(a) (c) =(d) ~The question was asked in an online interview.Asked question is from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct answer is (B) > |
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| 43. |
Calculate the value of safety factor using the data: tc=12 msec, tq=6 msec.(a) 4(b) 2(c) 3(d) 6This question was addressed to me in an online quiz.Asked question is from Solid-State Devices in division Introduction to Solid-State Devices of Electric Drives |
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Answer» Correct ANSWER is (b) 2 |
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| 44. |
SCR is a current controlled device.(a) True(b) FalseI had been asked this question in an international level competition.I want to ask this question from Solid-State Devices topic in division Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct answer is (a) True |
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| 45. |
The value of latching current is more than holding current.(a) True(b) FalseThe question was asked in unit test.This intriguing question comes from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» RIGHT choice is (a) True To EXPLAIN I would say: The latching current is the minimum anode current at which SCR starts CONDUCTING. HOLDING current is the anode below which SCR stops conduction. The latching current is 2-3 TIMES more than the holding current. |
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| 46. |
Calculate the compensator rating required for cos(Φ)=.35.(a) .936 P.U(b) .154 P.U(c) .481 P.U(d) .289 P.UThe question was posed to me in my homework.My question is taken from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» Right ANSWER is (a) .936 P.U |
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| 47. |
Calculate the work done in stretching the wire of volume=12 m^3 and the values of stress and strain are 28 N/m^2 and 7.(a) 1176 J(b) 1544 J(c) 2542 J(d) 8788 JThe question was posed to me during an online exam.The above asked question is from Solid-State Devices in chapter Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct option is (a) 1176 J |
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| 48. |
Calculate the value of α for β=.2.(a) .85(b) .15(c) .23(d) .16I had been asked this question in an interview.The question is from Solid-State Devices in division Introduction to Solid-State Devices of Electric Drives |
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Answer» CORRECT choice is (d) .16 Easiest explanation: The relationship between β and ∝ is ∝=β/(1+β)=.2÷1.2=.16. The CURRENT gain is the RATIO of the COLLECTOR current and base current. The value of α is Ic÷IE. |
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| 49. |
Calculate the value of Vpeak if crest factor=5 and Vr.m.s=4 V.(a) 20 V(b) 30 V(c) 40 V(d) 50 VI had been asked this question during an interview.The doubt is from Solid-State Devices in section Introduction to Solid-State Devices of Electric Drives |
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Answer» The correct OPTION is (a) 20 V |
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| 50. |
In a transistor, β=75 and Ic=53 mA. The value of IB is _____________(a) .70 mA(b) .25 mA(c) .26 mA(d) .15 mAThe question was posed to me in unit test.This interesting question is from Solid-State Devices in portion Introduction to Solid-State Devices of Electric Drives |
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Answer» CORRECT choice is (a) .70 mA The BEST I can explain: The VALUE of β is Ic÷IB. The value of IB=IE-Ic. The value of IB is Ic÷β=53÷75=.70 mA. The relationship between β and ∝ is β=∝/(1-∝). |
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