Electrical Engineering Interview Questions and Answers

  1. What is Main Difference b/w Electrical and Electronics Engineering?
  2. Why shunt capacitor bank used in substation?
  3.  Why all the voltage levels are multiples of 11 kV?
  4. What causes an electric shock, current or voltage?
  5. Why Motor rated in kW instead of kVA?
  6. How to convert KVA to KW?
  7. Why is AC considered more efficient than DC?
  8. What would happen if a transformer is connected to a DC supply?
  9.  What is the difference between a four point starter and three point starter? 
  10. What do you mean by the “bay” in a switchyard?
  11. What is meant by H.R.C fuse?
  12. What is the difference between an alternator and a generator?
  13. What are the advantages of star-delta starter with induction motor?
  14. Why Transformer Rated in kVA and not in kW?
  15. What is the function of a choke in tube light?
  16. What is the difference between Earthing and Grounding?
  17. What are the disadvantages of low power factor?
  18. What is the difference between a power transformer and a distribution transformer?
  19. List of equipment in substation
  20. Why the transformer is needed to be operated in parallel?
  21. If one lamp connects between two phases it will it glow or not?
  22. What happens when AC supply is given to DC machines?
  23.  Why star delta starter is preferred with induction motor?
  24.  Why AC rated in Tons, Not in kW or kVA?
  25. What are the differences between fuse and circuit breaker?
  26. What are instrument transformers?
  27. What is the difference between relay and circuit breaker?
  28. What is meant by knee point voltage of CT?
  29. Why Battery rated in Ah (Ampere hour) and not in VA?
  30. What is Electrical Engineering?
  31. What is the frequency of DC Voltage?
  32. What is the difference between MCB and MCCB?
  33. How do I know if a machine has a synchronous or an induction motor?
  34. Auto transformer, what are its use in a substation?
  35. What is Wave Trap?
  36. Why Power Plant Capacity Rated in MW and not in MVA?
  37. Why Generator & Alternator rated in kVA. Not in kW?
  38. What is the diffrence between DOL & RDOL starter?
  39. What is the difference between synchronous generator & asynchronous generator?
  40. Why stones are used in switch yard ?
  41. Why AC needs more insulation than DC at same voltage level?
  42. What is RDOL starter?
  43. Why battery can’t store AC supply?
  44. What happens when an DC supply is directly connected to an AC supply?
  45. What happens if we connect a AC supply to a capacitor?
  46. Why do we use high voltage to transmit electrical power?
  47. What happens if one phase is down in a high voltage transmission line?
  48.  What is the role of link in neutral in a three phase ac system?
  49. Why doesn’t neutral wire give a shock?
  50. How does a capacitor store energy?
  51. Mobile Substation, what is its purpose? 
  52. When a 60 W, 200 V bulb is connected in series with 100 W, 200 V bulb across a 200 V A.C. power supply, which bulb will glow brighter?
  53. What is the Purpose of Auxiliary Transformer in Substation?
  54. What happens when the supply frequency of a transformer increases?
  55. What is corona effect in transmission line?
  56. What is skin effect and proximity effect?
  57. What will happen when power factor is leading in distribution of power?
  58. What is an autorecloser in electric power distribution?
  59. Why Delta Star Transformers are used for Lighting Loads?
  60. What is a Trivector Meter? Where is it used?
  61. What is load shedding?
  62. Why do the positive and negative wires spark when touched?
  63. Why do we need a starter to start a DC motor?
  64. Which motor has high starting torque AC or DC?
  65. What is a capacitor bank and why is it used?
  66. Why are capacitors for power factor improvement generally connected in delta?
  67. What is Capacitive Voltage Transformer(CVT) ?
  68.  What is impedance triangle? 
  69. Why the capacitors works on ac only?
  70. Why the size of transformer decreases if we increases the frequency?
  71. Why does a humming sound occur in high voltage transmission lines?
  72. Why reactors are used in substations?
  73. What is an Anti Fuse ?
  74. Why do we use grounding transformer?
  75. What is the use of a conservator in transformer?
  76. Difference between blackout and load shedding?
  77. What is Horn Gap Fuse? Where it is used?
  78. What is an Earth Leakage Circuit Breaker (ELCB)?
  79. How to Calculate the suitable Capacitor size in Farads & kVAR for Power factor Improvement?
  80. What is a Lightning Arrester?
  81. What types of capacitors are used in a ceiling fan?
  82. What is Tap Changer?
  83. What is AVR (Automatic Voltage Regulation)?
  84. What are electrical wire color codes and what they indicates?
  85. Why should frequency be maintained in a power system?
  86. What is the need of synchronizing two different power sources?
  87. Why is magnetic locking or cogging not present in a DC motor?
  88. What are the common AC and DC motor tests?
  89. How can we change the direction of a DC motor?
  90. Can a DC motor be converted into a DC generator?
  91. What are applications of DC motors?
  92. What are the differences between a DC motor and an AC motor?
  93. Why twisted conductor used in transmission line?
  94. What are the parts of transmission line?
  95. Can synchronous generator generates reactive power?
  96. What is the application of reactive power?
  97. What does tripping means in transmission lines?p0ol
  98. What is the Difference between blackout and brownout in power system?
  99. What is cascaded failure in terms of transmission lines?
  100. Why does fog cause tripping of Transmission lines?
  101. What is the difference between phase and line voltage?
  102. What is real, reactive, and apparent power?
  103. How is reactive power produced? What are the effects of reactive power in the grid?
  104. What is difference between Load angle and Power angle?
  105. What is power angle in transmission line system?
  106. How does power factor affect power transmission line?
  107. Why is spiraling in transmission lines effective?
  108. What is charging current in transmission line?
  109. Why is reactive power compensation needed in a power system?
  110. What is the relation between reactive power and power factor?
  111. Why don’t we use copper in transmission lines?
  112. Do capacitive and inductive reactances cause losses in transmission lines?
  113. Why are overhead transmission lines not insulated?
  114. How does a capacitor correct a power factor?
  115. What happens when the capacitive reactance of a transmission line is very high?
  116. What is the importance of reactive power in transmission lines?
  117. What is difference between a feeder and transmission line?
  118. How does the capacitive nature of transmission lines affects its working?
  119. Why is the capacitance effect not present in short transmission lines?
  120. What is reactive power? What is the use of reactive power?

Leave a Reply

Your email address will not be published. Required fields are marked *