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
4251. The minimum charge on any object cannot be less than_______________?
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A. no definite value exist

B. 1.6 x 10-19C

C. 9.1 x 109C

D. 3.2 x 10-19C

4252. Dielectric constant for mica is nearly_____________?
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A. 200

B. 100

C. 1 to 2

D. 3 to 8
4253. If metallic conductor is charged negatively then its weight______________?
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A. Increases for a while

B. First increases then decreases

C. Remains same

D. Decreases then increases

4254. The minimum value of potential gradient in a cable occurs in____________?
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A. conductor

B. uniformly all over

C. outer sheath

D. insulation
4255. For closer tolerances which of the following capacitors is usually preferred ?
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A. Ceramic disc capacitor

B. Mica capacitor

C. None of the above

D. Paper capacitor

4256. A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is_____________?
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A. 0.6 F

B. 0.8 F

C. 0.12 F

D. 0.024 F
4257. Dielectric strength of mica is___________?
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A. 10 to 20 kV/mm

B. 30 to 50 kV/mm

C. 50 to 200 kV/mm

D. 300 to 500 kV/mm

4258. The value of the capacitance depends upon the________________?
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A. thickness of the capacitor plates

B. geometry of the capacitor

C. dinsity of the capacitor plates

D. voltage applied

4259. Electric intensity being a vector quantity always points_______________?
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A. opposite to the direction of force experienced by a unit positive charge

B. along the direction of force experienced by a unit positive charge

C. perpendicular to the direction of force experienced by a uit positive charge

D. any of above

4260. If an ohmmeter reading immediately goes practically to zero and stays there, capacitor is___________?
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A. satisfactory

B. charged

C. lossy

D. short-circuited
4261. Which of the following capacitors can be used for temperature compensation ?
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A. Paper capacitor

B. Air capacitor

C. None of the above

D. Ceramic capacitor
4262. The value of E within the field due to a point charge can be found with the help of___________?
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A. Kirchhoff s laws

B. Coulombs laws

C. Faradays laws

D. none of the above

4263. The electric lines of force are____________?
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A. depends upon case

B. physically existing every where

C. physically existing near the charges

D. imaginary
4264. In a capacitor, the electric charge is stored in_________?
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A. dielectric

B. dielectric as well as metal plates

C. metal plates

D. none of the above

4265. The process of heat transfer during the reentry of satellites and missiles, at very high speeds, into earths atmosphere is known as_______________?
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A. radiation

B. viscous dissipation

C. ablation

D. irradiation

4266. By the use of which of the following, high frequency power supply for induction furnaces can be obtained ?
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A. Current transformers

B. Coreless transformers

C. Multi-phase transformer

D. Motor-generator set
4267. For the transmission of heat from one body to another__________?
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A. temperature of the two bodies must be different

B. both bodies must be solids

C. both bodies must be in contact

D. at least one of the bodies must have some source of heating

4268. When a body reflects entire radiation incident on it, then it is known as____________?
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A. grey body

B. black body

C. white body

D. transparent body

4269. Ajax Wyatt furnace is started when____________?
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A. it is filled above core level

B. it is fully empty

C. it is filled below core level

D. none of the above

4270. _________ has the highest value of thermal conductivity?
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A. Brass

B. Copper

C. Steel

D. Aluminium

4271. Resistance variation method of temperature control is done by connecting resistance elements in_____________?
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A. series

B. parallel

C. series-parallel connections

D. all of the above ways

E. star-delta connections

4272. The material of the heating element for a furnace should have___________?
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A. lower melting point

B. high specific resistance

C. all of the above

D. higher temperature coefficient

4273. In heating the ferromagnetic material by induction heating, heat is produced due to_____________?
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A. induced current flow through the charge

B. none of the above factors

C. hysteresis loss taking place below curie temperature

D. due to hysteresis loss as well as eddy current loss takingplace in the charge
4274. For radiant heating around 2250C, the heating elements are made of____________?
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A. copper alloy

B. carbon

C. stainless steel alloy

D. tungsten alloy
4275. Which of the following is an advantage of heating by electricity ?
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A. All of the above

B. Higher efficiency

C. Absence of flue gases

D. Quicker operation

4276. Which of the following is an advantage of eddy current heating ?
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A. Heat at very high rate can be gene-rated

B. All of the above

C. The amount of heat generated can be controlled accurately

D. The area of the surface over which heat is produced can be accurately controlled

4277. Which of the following will happen if the thickness of refractory wall of furnace is increased ?
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A. Heat loss through furnace wall will increase

B. Energy consumption will increase

C. Temperature on the outer surface of furnace walls will drop

D. Temperature inside the furnace will fall

4278. Hysteresis loss and eddy current loss are used in____________?
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A. resistance heating

B. induction heating of brass

C. induction heating of steel

D. dielectric heating

4279. Which of the following methods of heating is not dependent on the frequency of supply ?
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A. Induction heating

B. All of the above

C. Dielectric heating

D. Electric resistance heating
4280. Which of the following heating methods has maximum power factor ?
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A. Arc heating

B. Resistance heating

C. Induction heating

D. Dielectric heating

4281. In direct arc furnace, which of the following has high value ?
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A. Power factor

B. All of the above

C. Voltage

D. Current
4282. In an electric room heat convector the method of heating used is______________?
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A. induction heating

B. dielectric heating

C. resistance heating

D. arc heating

4283. In resistance heating highest working temperature is obtained from heating elements made of_____________?
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A. silicon carbide

B. nickel copper

C. silver

D. nichrome

4284. A non-dimensional number generally associated with natural convection heat transfer is____________?
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A. Prandtl number

B. Pecelet number

C. Grashoff number

D. Nusselt number

4285. The temperature inside a furnace is usually measured by which of the following ?
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A. Optical pyrometer

B. Any of the above

C. Mercury thermometer

D. Alcohol thermometer

4286. Direct arc furnaces have which of the following power factors ?
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A. Unity

B. Low, leading

C. Low, lagging

D. Any of the above

4287. In an electric press mica is used_____________?
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A. as an insulator

B. as a device for power factor improvement

C. for induction heating

D. for dielectric heating

4288. Properly of low temperature co-eflficient of heating element is desired due to which of the following reasons ?
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A. To avoid initial rush of current

B. To avoid change in kW rating with temperature

C. Both (A) and (B)

D. Either (A) or (B)

4289. Which of the following methods is used to control temperature in resistance furnaces ?
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A. Periodical switching on and off of the supply

B. Variation of voltage

C. All of the above methods

D. Variation of resistance

4290. Induction furnaces are employed for which of the following ?
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A. Melting aluminium

B. Heat treatment of castings

C. Heating of insulators

D. None of the above

4291. In the indirect resistance heating method, maximum heat-transfer takes place by____________?
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A. conduction</strong>

B. any of the above

C. radiation

D. convection

4292. For heating element high resistivity material is chosen to______________?
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A. increase the life of the heating element

B. reduce the effect of oxidation

C. reduce the length of heating element

D. produce large amount of heat

4293. Which of the following has the highest value of thermal conductivity ?
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A. Melting ice

B. Water

C. Sold ice

D. Steam

4294. By which of the following methods the temperature inside arc nace can be varied ?
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A. By any of the above method

B. By varying the current through heating elements

C. By disconnecting some of the heating elements

D. By varying the operating voltage

4295. It is desirable to operate the arc furnaces at power factor of_____________?
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A. zero

B. 0.707 leading

C. unity

D. 0.707 lagging
4296. In a domestic cake baking oven the temperature is controlled by________________?
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A. voltage variation

B. auto-transformer

C. series-parallel operation

D. thermostat

4297. In a resistance furnace the atmosphere is_____________?
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A. deoxidising

B. reducing

C. neutral

D. oxidizing
4298. Heat is transferred simultaneously by condition, convection and radiation_____________?
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A. inside boiler furnaces

B. from refrigerator coils to freezer of a refrigerator

C. through the surface of the insulted pipe carrying steam

D. during melting of ice

4299. In electric press, mica is used because it is _________ conductor of heat but/and __________ conductor of electricity?
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A. good, good

B. bad, good

C. good, bad

D. bad, bad

4300. is used for heating non-conducting materials?
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A. Induction heating

B. Arc heating

C. Dielectric heating

D. Eddy current heating