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
651. Which of the following materials is used for overhead transmission lines ?
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A. Any of the above

B. Cadmium copper

C. Steel cored aluminium

D. Galvanised steel

652. Reheat cycle in steam power plant is used to________________?
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A. utilise heat of flue gases

B. improve condenser performance

C. reduce loss of heat

D. increase thermal efficiency
653. A feeder, in a transmission system, feeds power to________________?
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A. distributors

B. service mains

C. generating stations

D. all of the above

654. A uniformly-loaded D.C. distributor is fed at both ends with equal voltages. As compared to a similar distributor fed at one end only, the drop at the middle point is______________?
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A. none of the above

B. one-half

C. one-third

D. one-fourth

E. twice

655. The proper indication of incomplete combustion is_______________?
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A. the smoking exhaust from chimney

B. high CO content in flue gases at exit

C. high temperature of flue gases

D. high CO2 content in flue gases at exit

656. Demand factor is defined as___________?
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A. connected load/maximum demand.

B. average load x maximum load

C. maximum demand/connected load

D. average load/maximum load.

657. There is a greater possibility of occurence of corona during______________?
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A. humid weather

B. summer heat

C. dry weather

D. winter

E. none of the above

658. A gas turbine basically work on
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A. Dual cycle

B. Brayton cycle

C. Carnot cycle

D. Rankin cycle

659. In a substation the following equipment is not installed?
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A. voltatre transformers

B. shunt reactors

C. series capacitors

D. exciters
660. Electro-mechanical voltage regulators are generally used in___________?
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A. transformers

B. reactors

C. all of the above

D. generators
661. The percentage 02 by volume in atmosphere air is____________?
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A. 77%

B. 21%

C. 23%

D. 79%

662. In regenerative cycle feed water is heated by_____________?
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A. heaters

B. all above

C. draining steam from the turbine

D. exhaust gases

663. One kilowatt hour is equal to_________?
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A. 532 k cal.

B. 860 k cal.

C. 746 k cal.

D. 735 k cal.

664. The distributors for residential areas are______________?
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A. single phase

B. three-phase three wire

C. three-phase four wire

D. none of the above

665. Besides a method of trial and error, which of the following methods is employed for solution of network problems in interconnected system ?
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A. Superposition of currents

B. Direct application of Kirehhoffs laws

C. Circulating current method

D. All of the above

E. Thevenins theorem

666. Which of the following materials is not used for transmission and distribution of electrical power________________?
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A. Copper

B. Steel

C. Aluminium

D. Tungsten
667. In a surface condenser if air is removed, there is___________?
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A. fall in absolute pressure maintained in condenser

B. no change in absolute pressure in the condenser

C. rise in temperature of condensed steam

D. rise in absolute pressure maintained in condenser

668. Which of the following bus-bar schemes has the lowest cost?
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A. Single bus-bar scheme

B. Breaker and a half scheme

C. Ring bus-bar scheme

D. Main and transfer scheme

669. The isentropic expansion of steam through nozzle for the steam initially dry saturated at inlet is approximated by equation?
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A. pv = C

B. pv1A = C

C. pv

D. pv1i = C

670. The efficiency of a modern boiler using coal and heat recovery equipment is about_____________?
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A. 65 to 70%

B. 85 to 90%

C. 40 to 50%

D. 25 to 30%

671. Secondary air is the air used to______________?
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A. transport and dry the coal

B. provide air round the burners for getting optimum combustion

C. increase the flame length

D. reduce the flame length

672. Reduction in core losses and increase in permeability are obtained with transformer employing__________?
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A. none of the above

B. core built-up of laminations of cold rolled grain oriented steel

C. core built-up of laminations of hot rolled sheet

D. either of the above

673. The presence of ozone due to corona is harmful because it________________?
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A. reduces power factor

B. none of the above

C. gives odour

D. corrodes the material

E. transfer energy to the ground

674. Which of the following protection is normally not provided on small distribution transformers ?
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A. Overfluxing protection

B. All of the above

C. Buchholz relay

D. Overcurrent protection

675. A shell-type transformer has_________?
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A. none of the above

B. negligibly hysteresis losses

C. reduced magnetic leakage

D. high eddy current losses

676. In thermal power plant, heat from the flue gases is utilized in___________?
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A. economizer

B. condenser

C. super heater

D. chimney

677. The direction of rotation of a D.C. series motor can be changed by___________?
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A. None of the above

B. either of A. and B. above

C. interchanging field terminals

D. interchanging supply terminals

678. Rankine cycle efficiency of a good steam power plant may be in the range of____________?
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A. 15 to 20 per cent

B. 90 to 95 per ceut

C. 35 to 45 per cent

D. 70 to 80 per cent

679. A circuit is disconnected by isolators when____________?
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A. line is energized

B. circuit breaker is not open

C. there is no current in the line

D. line is on full load

680. Load factor of a power station is defined as____________?
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A. average load x maximum demand

B. maximum demand/average load

C. none of the above

D. average load/maximum demand
681. Due to which of the following reasons the cables should not be operated too hot ?
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A. Expansion of the oil may cause the sheath to burst

B. The oil may loose its viscosity and it may start drawing off from higher levels

C. The thermal instability may rise due to the rapid increase of dielectric losses with temperature

D. Unequal expansion may create voids in the insulation which will lead to ionization

E. All of the above
682. A 3-phase 4 wire system is commonly used on________________?
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A. primary transmission

B. primary distribution

C. secondary distribution

D. secondary transmission

683. In aluminium conductors, steel core is provided to____________?
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A. compensate for skin effect

B. reduce line inductance

C. increase the tensile strength

D. neutralise proximity effect

684. Which of the following is usually not the generating voltage__________?
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A. 6.6 kV

B. 11kV

C. 9.9 kV

D. 13.2kV

685. A Transformer transforms____________?
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A. current and voltage

B. power

C. voltage

D. current

686. The usual spans with R.C.C. poles are_______________?
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A. 300500 meters

B. 4050 meters

C. 60100 meters

D. 80100 meters
687. Which of the following methods is used for laying of underground cables ?
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A. Draw-in-system

B. Direct laying

C. All of the above

D. Solid system

688. The capacity of large turbo-generators varies from___________?
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A. 100 to 650 MW

B. 50 to 300 MW

C. 20 to 100 MW

D. 70 to 400 MW

689. Large industrial consumers are supplied electrical energy at__________________?
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A. 400 V

B. 11 kV

C. 400 kV

D. 66 kV

690. The speed of a D.C. shunt motor more than its full-load speed can be obtained by_____________?
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A. increasing the armature current

B. increasing the field current

C. decreasing the armature current

D. decreasing the field current
691. These days D.C. motors are widely used in____________?
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A. electric traction

B. air compressors

C. machine shops

D. pumping sets

692. Brushes of D.C. machines are made of_________?
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A. carbon

B. all of above

C. hard copper

D. soft copper

693. A series generator can self-excite:______________?
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A. only if the load current is zero

B. only if the load current is not zero

C. irrespective of the value of load current

D. none of the above

694. Which of the following losses are significantly reduced by laminating the core of a D.C. generator ?
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A. Eddy current losses

B. Copper losses

C. Windage losses

D. Hysteresis losses

695. While applying Flemings right-hand rule to And the direction of induced e.m.f., the thumb points towards___________?
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A. direction of motion of the conductor if forefinger points in the direction of generated e.m.f.

B. direction of flux

C. direction of induced e.m.f.

D. direction of motion of conductor, if forefinger points along the lines of flux
696. In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be_____________?
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A. rated full-load current

B. almost negligible

C. more than full-load current

D. less than full-load current

697. For constant torque drive which speed control method is preferred ?
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A. Field control

B. Shunt armature control

C. Mechanical loading system

D. Armature voltage control
698. In case of D.C. machine winding, number of commutator segments is equal to______________?
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A. number of armature turns

B. number of armature conductors

C. number of armature coil sides

D. number of armature coils
699. The condition for maximum efficiency for a D.C. generator is______________?
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A. copper losses = 0

B. hysteresis losses = eddy current losses

C. eddy current losses = stray losses

D. variable losses = constant losses
700. By looking at which part of the motor, it can be easily confirmed that a particular motor is D.C. motor?
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A. Stator

B. Shaft

C. Commutator

D. Frame