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
5251. The e.m.f. generated in a D.C. generator is directly proportional to____________?
comments icon0

A. number of poles

B. all of the above

C. speed of armature

D. flux/pole

5252. When two D.C. series generators are running in parallel, an equilizer bar is used________________?
comments icon0

A. to increase the speed and hence generated e.m.f.

B. to increase the series flux

C. so that two similar machines will pass approximately equal currents to the load

D. to reduce the combined effect of ar-mature reaction of both machines

5253. In a D.C. generator the ripples in the direct e.m.f. generated are reduced by_____________?
comments icon0

A. using conductor of annealed copper

B. using commutator with large number of segments

C. using carbon brushes of superior quality

D. using equiliser rings

5254. A D.C. welding generator has____________?
comments icon0

A. wave moving

B. lap winding

C. any of the above

D. duplex winding

5255. Shunt generators are most suited for stable parallel operation because of their______________?
comments icon0

A. identical voltage characteristics

B. rising voltage characteristics

C. drooping voltage characteristics

D. linear voltage characteristics

5256. The armature core of a D.C. generator is usually made of__________________?
comments icon0

A. copper

B. non-ferrous material

C. cast-iron

D. silicon steel
5257. Following D.C. generator will be in a position to build up without any residual magnetism in the poles______________?
comments icon0

A. series generator

B. shunt generator

C. self-excited generator

D. compound generator

5258. Open circuited armature coil of a D.C. machine is________________?
comments icon0

A. identified by the scarring of the commutator segment to which open circuited coil is connected

B. indicated by a spark completely around the commutator

C. both A. and (b)

D. none of the above

5259. The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be_____________?
comments icon0

A. 640 V

B. 600 V

C. 580 V

D. 620 V

5260. With a D.C. generator which of the following regulation is preferred ?
comments icon0

A. 50% regulation

B. 100% regulation

C. infinite regulation

D. 1% regulation
5261. Which of the following generator will have negligible terminal voltage while running on no-load?
comments icon0

A. Compound generator

B. Shunt generator

C. Series generator

D. Separately excited generator

5262. Iron losses in a D.C. machine are independent of variations in______________?
comments icon0
A. load

B. speed and voltage

C. voltage

D. speed

5263. Number of tappings for each equalizer ring is equal to_____________?
comments icon0

A. number of poles

B. number of parallel paths

C. number of commutator segments

D. number of pole pairs
5264. Iron losses in a D.C. machine are independent of variations in_____________?
comments icon0

A. speed

B. voltage

C. load

D. speed and voltage

5265. A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave will_____________?
comments icon0

A. will be of 5 xiVHz

B. will be of 5 Hz

C. will be of v Hz 5

D. will be zero

5266. In a commutator_____________?
comments icon0

A. mica and copper are equally hard

B. mica is harder than copper

C. none of the above

D. copper is harder than mica

5267. A cumulatively compounded long shunt generator when operating as a motor would be____________?
comments icon0

A. cumulatively compounded short shunt

B. cumulatively compounded long shunt

C. differentially compounded short shunt

D. deferentially compounded long shunt
5268. According to Flemings right-hand rule for finding the direction of induced e.m.f., when middle finger points in the direction of induced e.m.f., forefinger will point in the direction of____________?
comments icon0
A. lines of force

B. either of the above

C. none of the above

D. motion of conductor

5269. A D.C. generator works on the principle of____________?
comments icon0
A. Faradays law of electromagnetic induction

B. Lenzs law

C. none of the above

D. Ohms law

5270. In over compounded generator, full load terminal voltage is______________?
comments icon0

A. less than no load terminal voltage

B. equal to no-load terminal voltage

C. almost zero

D. more than no load terminal voltage
5271. In the depletion region of a pn junction, there is a shortage of_________________?
comments icon0

A. Donor ions

B. None of the above

C. Acceptor ions

D. Holes and electrons
5272. A semiconductor has ______________ temperature coefficient of resistance?
comments icon0

A. Zero

B. None of the above

C. Negative

D. Positive

5273. The resistivity of a pure silicon is about _______________?
comments icon0
A. 6000 O cm

B. 6 x 10-8 O cm

C. 100 O cm

D. 3 x 105 O m

5274. A reverse bias pn junction has_____________?
comments icon0

A. Very narrow depletion layer

B. Almost no current

C. Large current flow

D. Very low resistance

5275. The resistivity of pure germanium under standard conditions is about_______________?
comments icon0

A. 6 x 10-4 cm

B. 60 x cm

C. 6 x 104 cm

D. 3 x 106 cm

5276. The leakage current in a pn junction is of the order of________________?
comments icon0

A. kA

B. mA

C. Aa

D. A
5277. The leakage current across a pn junction is due to________________?
comments icon0
A. Minority carriers

B. Junction capacitance

C. Majority carriers

D. None of the above

5278. A hole and electron in close proximity would tend to________________?
comments icon0

A. None of the above

B. Repel each other

C. Attract each other

D. Have no effect on each other

5279. The random motion of holes and free electrons due to thermal agitation is called______________?
comments icon0
A. Diffusion

B. None of the above

C. Pressure

D. Ionisation

5280. Addition of pentavalent impurity to a semiconductor creates many________________?
comments icon0

A. Bound electrons

B. Valence electrons

C. Free electrons

D. Holes

5281. In an intrinsic semiconductor, the number of free electrons_____________?
comments icon0

A. None of the above

B. Is greater than the number of holes

C. Is less than the number of holes

D. Equals the number of holes
5282. When the temperature of an extrinsic semiconductor is increased, the pronounced effect is on_________________?
comments icon0

A. Junction capacitance

B. Minority carriers

C. Majority carriers

D. None of the above

5283. At absolute temperature, an intrinsic semiconductor has________________?
comments icon0

A. Many free electrons

B. A few free electrons

C. No holes or free electrons

D. Many holes

5284. The barrier voltage at a pn junction for germanium is about________________?
comments icon0
A. 0.3 V

B. 5 V

C. 3 V

D. Zero

5285. With forward bias to a pn junction , the width of depletion layer__________________?
comments icon0

A. Increases

B. Decreases

C. Remains the same

D. None of the above

5286. As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor_______________?
comments icon0
A. Decreases

B. Remains the same

C. Increases

D. None of the above

5287. In a semiconductor, current conduction is due to________________?
comments icon0

A. None of the above

B. Holes and free electrons

C. Only holes

D. Only free electrons

5288. A semiconductor is formed by ______________bonds?
comments icon0

A. None of the above

B. Co-ordinate

C. Electrovalent

D. Covalent
5289. The impurity level in an extrinsic semiconductor is about_______________of pure semiconductor ?
comments icon0

A. 1 atom for 100 atoms

B. 1 atom for 108 atoms

C. 1 atom for 104 atoms

D. 10 atoms for 108 atoms

5290. Addition of trivalent impurity to a semiconductor creates many_______________?
comments icon0

A. Free electrons

B. Bound electrons

C. Valence electrons

D. Holes
5291. The battery connections required to forward bias a pn junction are_________________?
comments icon0

A. None of the above

B. +ve terminal to p and ve terminal to n

C. #NAME?

D. #NAME?

5292. At room temperature, an intrinsic semiconductor has_______________?
comments icon0
A. A few free electrons and holes

B. No holes or free electrons

C. Many free electrons only

D. Many holes only

5293. A pentavalent impurity has______________Valence electrons?
comments icon0

A. 4

B. 3

C. 6

D. 5
5294. A forward biased pn junction diode has a resistance of the order of_____________?
comments icon0
A. O

B. kO

C. None of the above

D. MO

5295. A hole in a semiconductor is defined as_________________?
comments icon0

A. strong>. A free proton

B. The incomplete part of an electron pair bond

C. A free electron

D. A free neutron

5296. When a pure semiconductor is heated, its resistance_________________?
comments icon0

A. Remains the same

B. Goes up

C. Cant say

D. Goes down
5297. The strength of a semiconductor crystal comes from______________?
comments icon0

A. Forces between protons

B. Electron-pair bonds

C. None of the above

D. Forces between nuclei

5298. The most commonly used semiconductor is________________?
comments icon0

A. Sulphur

B. Germanium

C. Silicon

D. Carbon

5299. When a pentavalent impurity is added to a pure semiconductor, it becomes________________?
comments icon0

A. An intrinsic semiconductor

B. An insulator

C. n-type semiconductor

D. p-type semiconductor

5300. A trivalent impurity has______________valence electrons?
comments icon0

A. 5

B. 6

C. 4

D. 3