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
1601. Capacitance grading of cable implies__________?
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A. cables using single dielectric in different concentrations

B. none of the above

C. grading according to capacitance of cables per km length

D. use of dielectrics of different permeabilities

E. capacitance required to be introduced at different lengths to counter the effect of inductance

1602. It is noticed that durum charging___________?
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A. specific gravity of H2SO4 is increased

B. the anode becomes chocolate brown in colour (PbCfe) and cathode becomes grey metallic lead (Pb)

C. energy is absorbed by the cell

D. there is a rise in voltage

E. all of the above
1603. During the idle period of the battery, strong electrolyte tends to change the active material of the cell into____________?
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A. Pb02

B. PbSC-4

C. Pb

D. PbO

1604. Lead-acid cell has a life of nearly charges and discharges______________?
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A. 500

B. 1250

C. 1000

D. 700

1605. The best indication about the state of charge on a lead-acid battery is given by____________?
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A. specific gravity of electrolyte

B. output voltage

C. none of the above

D. temperature of electrolyte

1606. The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is__________?
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A. 22 kW

B. 64 kW

C. 32 kW

D. 12 kW

1607. Over charging______________?
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A. produces excessive gassing

B. increases the temperature resulting in buckling of plates

C. loosens the active material

D. all above
1608. At very low frequencies a series R-C circuit behaves as almost purely___________?
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A. resistive

B. none of the above

C. capacitive

D. inductive

1609. Pure inductive circuit takes power from the A.C. line when_________?
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A. applied voltage decreases but current increases

B. applied voltage increases but current decreases

C. both applied voltage and current increase

D. both applied voltage and current decrease

1610. For the same peak value, which of the following wave has the least mean value ?
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A. square wave

B. half wave rectified sine wave

C. sine wave

D. triangular wave

1611. The r.m.s. value and mean value is the same in the case of___________?
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A. sine wave

B. square wave

C. triangular wave

D. half wave rectified sine wave

1612. In an AC. circuit, a low value of kVAR compared with kW indicates_________?
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A. low efficiency

B. maximum load current

C. unity power factor

D. high power factor
1613. Dielectric strength of rubber is around____________?
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A. 15 kV/mm

B. 5 kV/mm

C. 30 kV/mm

D. 200 kV/mm

1614. If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be_______________?
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A. 5 kV/mm

B. 30 kV/mm

C. 15 kV/mm

D. 10 kV/mm
1615. In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of__________?
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A. R only

B. R,LorC

C. L only

D. C only

E. LorC
1616. Battery container should be acid resistance, therefore it is made up of___________?
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A. all above

B. wood

C. plastic

D. glass

1617. The internal resistance of an alkali cell is nearly _________ times that of the lead-acid cell
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A. five

B. two

C. four

D. three

1618. Those substances of the cell which take active part in chemical combination and hence produce electricity during charging or discharging are known as________materials
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A. active

B. inert

C. passive

D. redundant

1619. Which of the following circuit component opposes the change in the circuit voltage ?
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A. Conductance

B. Resistance

C. Inductance

D. Capacitance
1620. Which of the following waves has the highest value of peak factor ___________?
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A. Triangular wave

B. Half wave rectified sine wave

C. Square wave

D. Sine wave

1621. The disadvantage with paper as insulating material is____________?
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A. it is an organic material

B. it is hygroscopic

C. none of the above

D. it has high capacitance

1622. Internal resistance of a cell is reduced by__________?
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A. increasing the plate area

B. using vent plug to permit gas formed during discharge

C. putting plates very close together

D. all above methods
1623. Power factor of the system is kept high__________?
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A. to reduce line losses

B. due to all above reasons

C. to maximise the utilization of the capacities of generators, lines and transformers

D. to reduce voltage regulation of the line

1624. Aphasoris________?
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A. a coloured tag or band for distinction between different phases of a 3-phase supply

B. a line representing the magnitude and direction of an alternating quantity

C. an instrument used for measuring phases of an unbalanced 3-phase load

D. a line which represents the magnitude and phase of an alternating quantity
1625. In the cables, the location of fault is usually found out by comparing____________?
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A. the resistance of the conductor

B. the inductance of conductors

C. the capacitances of insulated conductors

D. all above parameters

1626. The purpose of a parallel circuit resonance is to magnify________?
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A. power

B. current

C. voltage

D. frequency

1627. Which of the following protects a cable against mechanical injury___________?
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A. Bedding

B. Armouring

C. Sheath

D. None of the above

1628. The time constant of a series R-C circuit is given by____________?
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A. R2C

B. R/C

C. RC

D. RC2

1629. Cables, generally used beyond 66 kV are___________?
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A. armoured

B. oil filled

C. S.L. type

D. belted

1630. Charging a sulphated battery at high rate results in___________?
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A. warping of plates

B. boiling of electrolyte due to gassing

C. all above

D. damage to separators, cell caps covers and battery case due to excessive temperature

1631. The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is_________?
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A. 8 kVAR

B. 16 kVAR

C. 6 kVAR

D. 4 kVAR

1632. The current flow through electrolyte is due to the movement of____________?
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A. none of the above

B. holes

C. ions

D. electrons

1633. The time constant of the capacitance circuit is defined as the time during which voltage________?
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A. rises to 63.2% of its final steady value

B. falls to 36.8% of its final steady value

C. none of the above

D. rises to 38.6% of its final steady value

1634. During charging the specific gravity of the electrolyte of a lead-acid battery
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A. increases

B. becomes zero

C. decreases

D. remains the same

1635. Natural rubber is obtained from milky sap of tropical trees
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A. Yes

B. No

1636. cables are used for 132 kV lines____________?
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A. High tension

B. Extra high tension

C. Extra super voltage

D. Super tension

1637. Power factor of the following circuit will be zero__________?
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A. resistance

B. inductance

C. capacitance

D. both B. and C.
1638. In capacitance grading of cables we use a _______ dielectric?
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A. composite

B. hygroscopic

C. porous

D. homogeneous

1639. The ampere-hour efficiency of a lead acid cell is normally between_________?
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A. 20 to 30%

B. 60 to 70%

C. 40 to 50%

D. 90 to 95%
1640. It is noticed that during discharging the following does not happen___________?
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A. both anode and cathode become PbS04

B. specific gravity of H2SO4 decreases

C. voltage of the cell decreases

D. the cell absorbs energy

1641. In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters ______?
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A. 220V3V

B. 220 V

C. 220/V3 V

D. none of the above

1642. In the case of an unsymmetrical alternating current the average value must always be taken over__________?
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A. the whole cycle

B. the half cycle

C. the quarter cycle

D. unsymmetrical part of the wave form

1643. In single core cables armouring is not done to________?
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A. avoid excessive sheath losses

B. none of the above

C. either of the above

D. make it flexible

1644. The insulating material should have____________?
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A. high resistivity

B. low permittivity

C. all of the above

D. high dielectric strength

1645. In congested areas where excavation is expensive and inconvenient draw in system of laying of underground cables is often adopted
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A. No

B. Yes

1646. In an A.C. circuit power is dissipated in____________?
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A. inductance only

B. resistance only

C. capacitance only

D. none of the above

1647. Which of the following refers to a parallel circuit ?
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A. The equivalent resistance is greater than any one of the resistors

B. The voltage across element is in proportion to its resistance value

C. The current through each element is same

D. The current through any one element is less than the source current
1648. Solid type cables are considered unreliable beyond 66 kV because___________?
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A. there is a danger of breakdown of insulation due to the presence of voids

B. skin effect dominates on the conductor

C. of corona loss between conductor and sheath material

D. insulation may melt due to higher temperature

1649. In a lead-acid cell, if the specific gravity of sulphuric acid is 1.8, it will require following ratio of acid to water to get mixture of specific gravity of 1.3
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A. 4 parts of acid to 8 parts of water

B. 6 parts of acid to 4 parts of water

C. 4 parts of acid to 6 parts of water

D. 4 parts of acid to 4 parts of water

1650. Conduit pipes are normally used to protect _______ cables
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A. PVC sheathed cables

B. all of the above

C. armoured

D. unsheathed cables