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
1651. The r.m.s. value of half wave rectified sine wave is 200 V. The r.m.s. value of full wave rectified AC. will be___________?
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A. 141.4 V

B. 282.8 V

C. 111 V

D. 100 V

1652. The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity. The statement is associated with____________?
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A. Gausss law

B. Newtons law

C. Faradays law of electromagnetic

D. Faradays law of electrolysis
1653. Excessive charging a battery tends to____________?
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A. bring about all above changes

B. produce gassing

C. to corrode the positive plates into lead peroxide thereby weakening them physically

D. increase the internal resistance of the battery

1654. The insulating material for cables should____________?
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A. have all above properties

B. be non-inflammable

C. be acid proof

D. be non-hygroscopic

1655. For a frequency of 200 Hz, the time period will be__________?
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A. 0.05 s

B. 0.5 s

C. 0.0005 s

D. 0.005 s
1656. Empire tape is__________?
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A. vulcanised rubber

B. impregnated paper

C. varnished cambric

D. none of the above

1657. Level of electrolyte in a cell should be ________ the level of plates
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A. equal to

B. above

C. none of the above

D. below

1658. The internal resistance of a lead-acid cell is that of Edison cell____________?
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A. equal to

B. none of the above

C. more than

D. less than
1659. The substances which combine together to store electrical energy during the charge are called ________ materials
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A. active

B. dielectric

C. inert

D. passive

1660. Time constant of an inductive circuit_________?
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A. increases with increase of inductance and decrease of resistance

B. increases with decrease of inductance and increase of resistance

C. increases with the increase of inductance and the increase of resistance

D. increases with the decrease of inductance and decrease of resistance

1661. The electrostatic stress in underground cables is_________?
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A. none of the above

B. same at the conductor and the sheath

C. zero at the conductor as well as on the sheath

D. maximum at the conductor and minimum at the sheath

E. minimum at the conductor and maximum at the sheath

1662. Mercury cell has which of the following characteristics ____________?
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A. Flat discharge current-voltage curve

B. All of the above

C. High power to weight ratio

D. Comparatively longer shelf life under adverse conditions of high temperature and humidity

1663. Low tension cables are generally used up to___________?
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A. 500 V

B. 1000 V

C. 200 V

D. 700 V

1664. On the average the ampere-hour efficiency of an Edison cell is about__________?
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A. 80%

B. 70%

C. 60%

D. 40%

1665. Time constant of a circuit is the time in seconds taken after the application of voltage to each___________?
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A. 90% of the maximum value

B. 25% of maximum value

C. 63% of maximum value

D. 50% of maximum value

1666. Pure inductive circuit____________?
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A. takes power from the line during some part of the cycle and then returns back to it during other part of the cycle

B. does not take power at all from a line

C. consumes some power on average

D. none of the above

1667. Extent of corrosion in the underground metal work depends upon___________?
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A. type of metals

B. type of soil chemicals

C. all above factors

D. amount of moisture

1668. Magnitude of current at resonance in R-L-C circuit________?
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A. depends upon the magnitude of R, Land C

B. depends upon the magnitude of C

C. depends upon the magnitude of L

D. depends upon the magnitude of R
1669. PVC stands for____________?
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A. none of the above

B. polyvinyl chloride

C. pressed and varnished cloth

D. post varnish conductor

E. positive voltage conductor

1670. Which of the following primary cells has the lowest voltage_________ ?
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A. Lithium

B. Carbon-zinc

C. Zinc-chloride

D. Mercury
1671. Ohm is unit of all of the following except___________?
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A. capacitive reactance

B. resistance

C. capacitance

D. inductive reactance

1672. Five 2 V cells are connected in parallel. The output voltage is__________?
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A. 1 V

B. 2 V

C. 1.75 V

D. 1.5 V

1673. The advantage of oil filled cables is_________?
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A. smaller overall size

B. more perfect impregnation

C. no ionisation, oxidation and formation of voids

D. all of the above
1674. The bedding on a cable consists of____________?
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A. none of the above

B. jute

C. any of the above

D. hessian cloth

1675. If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be______________?
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A. 400 cm

B. 10 cm

C. 2 cm

D. 50 cm
1676. Dry cell is modification of____________?
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A. Lead-acid cell

B. Deniell cell

C. Edison cell

D. Leclanche cell
1677. The phosphors for which of the following pair are 180 out of phase for VL, VC and VR______?
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A. Vc and VR

B. Vc and VL

C. VL and VR

D. none of the above

1678. The relative permittivity of rubber is____________?
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A. between 8 and 10

B. between 12 and 14

C. between 5 and 6

D. between 2 and 3
1679. In order that a hydrometer may float vertically in electrolyte its C.G. should be___________?
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A. displaced sideways

B. lowered

C. raised

D. undisturbed

1680. At _______ frequencies the parallel R-L circuit behaves as purely resistive
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A. very low

B. high

C. very high

D. low

1681. The ratio of ampere-hour efficiency to watt-hour efficiency of a lead-acid cell is____________?
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A. just one

B. none of the above

C. always greater than one

D. always less than one

1682. In any A.C. circuit always__________?
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A. actual power is more than reactive power

B. reactive power is more than actual power

C. reactive power is more than apparent power

D. apparent power is more than actual power
1683. Ampere hour capacity of an industrial battery is based on _______ hours discharge rate
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A. 8

B. 12

C. 16

D. 24

1684. Charging of sulfated battery produces _________ heat
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A. no

B. less

C. very little

D. more
1685. A parallel AC. circuit in resonance will__________?
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A. have a high voltage developed across each inductive and capacitive section

B. have a high impedance

C. have current in each section equal to the line current

D. act like a resistor of low value

1686. Which of the following primary cells has the highest voltage___________ ?
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A. Lithium

B. Carbon-zinc

C. Manganese-alkaline

D. Mercury

1687. During discharge, the active material of both the positive and negative plates is changed to___________?
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A. PbO

B. PbS04

C. Pb

D. Pb02

1688. The active material of the positive plates of silver-zinc batteries is_________?
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A. lead

B. zinc powder

C. silver oxide

D. lead oxide

1689. Capacitive susceptance is a measure of__________?
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A. reactive power in a circuit

B. the extent of neutralisation of reactive power in a circuit

C. a purely capacitive circuits ability to pass current

D. a purely capacitive circuits ability to resist the flow of current

1690. The frequency of domestic power supply in Pakistan is_________?
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A. 50 Hz

B. 100 Hz

C. 200 Hz

D. 60 Hz

1691. Time constant of an inductive circuit___________?
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A. increases with increase of inductance and decrease of resistance

B. increases with the increase of inductance and the increase of resistance

C. increases with decrease of inductance and decrease of resistance

D. increases with decrease of inductance and increase of resistance

1692. The advantage of cables over overhead transmission lines is___________?
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A. easy maintenance

B. can be used in congested areas

C. can be used in high voltage circuits

D. low cost

1693. When the specific gravity of the electrolyte of a lead-acid cell is reduced to 1.1 to 1.15 the cell is in___________?
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A. charged state

B. discharged state

C. both (A) and (B)

D. active state

1694. The total electric flux through any closed surface surrounding charges is equal to the amount oflcharge enclosed. The above statement is associated with____________?
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A. Gausss law

B. Coulombs square law

C. Maxwells first law

D. Maxwells second law

1695. In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of______________?
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A. synchronous motor

B. synchronous generator

C. induction regulator

D. shunt motor

1696. A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is___________?
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A. 350 mH

B. 3500 mH

C. 150 mH

D. 250 mH

1697. capacitors are used in transistor circuits?
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A. Electrolytic

B. Ceramic

C. Paper

D. Air

1698. In a lead-acid battery the energy is stored in the form of___________?
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A. electrostatic energy

B. chemical energy

C. charged ions

D. electromagnetic energy

1699. The minimum value of potential gradient in a cable occurs in____________?
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A. outer sheath

B. uniformly all over

C. insulation

D. conductor

1700. The capacitance between two plates increases with____________?
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A. shorter plate area and higher applied voltage

B. shorter plate area and shorter distance between them

C. larger plate area and shorter distance between plates

D. larger plate area, longer distance between plates and higher,applied voltage