ECET EEE Model Paper 4

1. Maximum rectification efficiency for a half wave rectifier is

A. 100%
B. 88%
C. 50%
D. 40.6%

Answer : D. 40.6%
Explanation:-

2. As a result of negative feedback is amplifier

A. Harmonic distortion reduces
B. Band width reduces
C. Noise increase
D. All of the above occur

Answer : A. Harmonic distortion reduces
Explanation:-

3. How many bytes does a 48K computer memory contain

A. 47256
B. 48000
C. 48512
D. 49512

Answer : D. 49512
Explanation:-

4. The one’s compliment of a binary number can be found by

A. Changing all one’s to zero’s
B. Changing all zero’s to one’s
C. Changing all one’s to zero’s and all zero’s to one’s
D. A in case of even numbers and B in case of odd numbers

Answer :C. Changing all one’s to zero’s and all zero’s to one’s
Explanation:-

5. Maximum regulation of a transformer occurs at

A. Rated KVA of transformer
B. Unity power factor
C. Lagging power factor
D. Leading power factor

Answer : C. Lagging power factor
Explanation:-

6. Unbalanced 3- phase stator currents cause

A. Double frequency currents in the rotor
B. Heating of rotor
C. Vibrations
D. All of the above

Answer : D. All of the above
Explanation:-

7. Two transformers are connected in parallel and share loads in the ratio of their KVA rating when their ohmic impedances

A. Purely reactive
B. Equal
C. In direct ratio of their ratings
D. In inverse ratio of their rating

Answer : D. In inverse ratio of their rating
Explanation:-

8. The reactance of a transformer depends on

A. Size of the core
B. Size of the tank
C. Leakage flux
D. All of the above

Answer : C. Leakage flux
Explanation:-

9. In case of a uniformly distributed winding the value of distortion factor is

A. 0.995
B. 0.80
C. 0.75
D. 0.50

Answer : A. 0.995
Explanation:-

10. In an alternator, the voltage drops occurs in

A. Armature resistance only
B. Armature resistance, leakage reactance
C. Armature resistance, leakage reactance and armature reaction
D. Armature resistance, leakage reactance, armature reaction and earth connections

Answer : C. Armature resistance, leakage reactance and armature reaction
Explanation:-

11. A synchronous motor is said to be floating when it operates

A. On no load and without losses
B. On constantly varying load
C. On pulsating load
D. On high load and variable supply voltage

Answer : A. On no load and without losses
Explanation:-

12. The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is

A. 60 Hz
B. 50 Hz
C. 25 Hz
D. 32/3 Hz

Answer : D. 32/3 Hz
Explanation:-

13. The type of dc generator use for arc welding purposes is a

A. Series generator
B. Shunt generator
C. Cumulatively compounded generator
D. Differentially compounded generator

Answer : A. Series generator
Explanation:-

14. The address to which a software or hardware restart branches is known as

A. Vector location
B. SID
C. SOD
D. TRAP control

Answer : D. TRAP control
Explanation:-

15. The generic micro-processor contains a zero and a carry flag. These are located on the

A. Interrupt
B. Status register
C. Either A or B above
D. None of the above

Answer : D. None of the above
Explanation:-

16. What is the direction of control bus

A. Unidirectional into microprocessor
B. Unidirectional out of microprocessor
C. Bi directional
D. Mixed direction i.e. some lines into microprocessor and some others out of microprocessor

Answer : D. Mixed direction i.e. some lines into microprocessor and some others out of microprocessor
Explanation:-

17. The speed of a series wound dc motor

A. Can be controlled by shunt field regulator
B. Cannot be controlled by diverter
C. Increases as a flux decreases
D. Increases as armature circuit resistance increases

Answer : C. Increases as a flux decreases
Explanation:-

18. Regenerative braking of on shunt motors used when

A. The load is variable
B. The load is constantly decreasing
C. The load has overhauling characteristics
D. The load has acts as a braking force

Answer :C. The load has overhauling characteristics
Explanation:-

19. DC machines are generally designed for maximum efficiency

A. Around full load
B. At 50% load
C. At 132/3 % load
D. At all loads

Answer :A. Around full load
Explanation:-

20. The efficiency of a 430, 200V transformer at full load is 0.8p.f lagging is 95%. The efficiency at full load 0.8p.f leading will be

A. 99%
B. 95.5%
C. 95%
D. 90%

Answer : C. 95%
Explanation:-

21. The voltage at the terminals of a dc series generator running at rated speed and no load will be

A. More than rated voltage
B. Full rated voltage
C. Very small voltage
D. Zero

Answer : C. Very small voltage
Explanation:-

22. In synchronous motor hunting can be minimized

A. By using damper bars
B. By using fly wheel
C. By designing the motor for adequate synchronizing power
D. By any of the above methods

Answer : D. By any of the above methods
Explanation:-

23. In an alternator if the armature reaction produces demagnetization of the main field, the power factor should be

A. Zero lagging
B. Zero leading
C. Unity
D. None of the above

Answer :A. Zero lagging
Explanation:-

24. The leakage flux in a transformer depends upon

A. Load current
B. Load current and voltage
C. Load current, voltage and frequency
D. Load current, voltage, frequency and power factor

Answer : A. Load current
Explanation:-

25. The rotor output of an induction motor is 15kW and the slip is 4%. Then the rotor copper loss is

A. 300W
B. 600W
C. 700W
D. 1200W

Answer : B. 600W
Explanation:-

26. An induction motor may get over heated due to

A. Low supply voltage
B. Over loading
C. Loss of ventilation
D. Any of the above

Answer : D. Any of the above
Explanation:-

27. In a synchronous motor with field under excited, the power factor will be

A. Leading
B. Lagging
C. Unity
D. None of the above

Answer :B. Lagging
Explanation:-

28. How many lines are there in data bus of 8085

A. 6
B. 8
C. 12
D. 16

Answer : B. 8
Explanation:-

29. Which of the following parameters of an induction motor varies inversely as the supply frequency

A. Full load speed
B. Starting current
C. Slip
D. Maximum running torque

Answer :D. Maximum running torque
Explanation:-

30. Which of the following is used on single phase hermetic motors

A. Voltage coil
B. Hot wire
C. Current coil
D. All of the above

Answer : A. Voltage coil
Explanation:-

31. Geothermal energy is

A. A renewable energy source
B. Alternative energy source
C. Inexhaustible energy source
D. Any of the above

Answer : D. Any of the above
Explanation:-

32. The ratio of maximum demand of the installation to sum of the individual maximum demand is known as

A. Demand factor
B. Plant use factor
C. Diversity factor
D. Plant capacity factor

Answer : C. Diversity factor
Explanation:-

33. The life of underground cable is taken as

A. 1 year
B. 2 years
C. 10 years
D. 40 years

Answer : D. 40 years
Explanation:-

34. The depreciation on the plant is charged by

A. Straight line method
B. Sinking fund method
C. Diminishing value method
D. All of the above

Answer : D. All of the above
Explanation:-

35. Pressure of steam in condenser is

A. Atmospheric pressure
B. Slightly more than atmospheric pressure
C. Slightly less than atmospheric pressure
D. Much less than atmospheric pressure

Answer :D. Much less than atmospheric pressure
Explanation:-

36. In a pumped storage

A. Power is produced by means of pumps
B. Water is stored by pumping of high pressure
C. Downstream water is pumped up during off load periods
D. Water is re circulated through turbine

Answer : C. Downstream water is pumped up during off load periods
Explanation:-

37. Ash content of coal can be reduced by

A. Slow burning
B. Washing
C. Pulverising
D. Mixing with high grade coal

Answer :B. Washing
Explanation:-

38. In India least share of power is provided by

A. Thermal power plant
B. Hydro electric power plants
C. Nuclear power plants
D. Diesel power plants

Answer : D. Diesel power plants
Explanation:-

39. Low utilization factor for a plant indicates that

A. Plant is under maintenance
B. Plant is used for stand by purpose only
C. Plant is used for base load only
D. Plant is used for peak load as well as base load

Answer :B. Plant is used for stand by purpose only
Explanation:-

40. In a thermal power plant , heat from the flue gases is recovered in

A. Chimney
B. Desuperheater
C. Economizer
D. Condenser

Answer : C. Economizer
Explanation:-

41. The following motor is popularly used in driving a refrigerator

A. Dc shunt motor
B. Universal motor
C. Plain cage Induction motor
D. Squirrel cage induction motor

Answer : B. Universal motor
Explanation:-

42. Motor is used for driving a tape recorder is

A. Hysteresis motor
B. Synchronous motor
C. Induction motor
D. Universal motor

Answer : A. Hysteresis motor
Explanation:-

43. Speed of repulsion motor at no load is

A. Low
B. Very low
C. High
D. Dangerously high

Answer : D. Dangerously high
Explanation:-

44. In a three phase 400 V, 50Hz, 1450 rpm motor is run on 360V, 45 Hz supply, then the torque will be

A. Unchanged
B. Reduced by 20%
C. Increased by 20%
D. Increased by 10%

Answer : A. Unchanged
Explanation:-

45. Isolators are used to disconnect a circuit when

A. Line is on full load
B. Line is energised
C. Circuit breaker is not open
D. There is no current in the line

Answer : D. There is no current in the line
Explanation:-

46. The main advantage of ac transmission system over dc transmission system is

A. Easy transformation
B. Less losses in transmission over along distance
C. Less insulation problems
D. Less problems of instability

Answer : B. Less losses in transmission over along distance
Explanation:-

47. In a substation the equipment is used to limit short circuit current level is

A. Series reactor
B. Coupling capacitor
C. Lightening switch
D. Isolator

Answer : A. Series reactor
Explanation:-

48. The fact that the conductor carries more current on the surface as compared to core is known as

A. Skin effect
B. Corona
C. Permeability
D. Unsymmetrical fault

Answer : A. Skin effect
Explanation:-

49. A relay used for short transmission line is

A. Reactance relay
B. Mho’s relay
C. Impedance relay
D. None of the above

Answer :A. Reactance relay
Explanation:-

50. In a plasma state a gas

A. Loses electrical conductivity
B. Conducts electricity
C. Becomes perfect insulator
D. Attracts moisture

Answer : B. Conducts electricity
Explanation:-

51. Glare is the result of

A. Very low luminance
B. Normal luminance
C. Excessive luminance
D. None of the above

Answer : C. Excessive luminance
Explanation:-

52. Glow lamps

A. Have cold cathode
B. Have hot cathode
C. Cannot withstand shocks
D. Consume high power

Answer : A. Have cold cathode
Explanation:-

53. A drive suitable for mines where explosive gas exists is

A. Diesel engine
B. Steam engine
C. Battery locomotive
D. Any of the above

Answer : C. Battery locomotive
Explanation:-

54. In a domestic cake baking oven the temperature is controlled by

A. Series parallel operation
B. Auto transformer
C. Thermostat
D. Voltage variation

Answer :C. Thermostat
Explanation:-

55. Heavy duty cranes are used in

A. Heavy engineering workshops
B. Steel plants
C. Ore handling plants
D. All of the above

Answer : D. All of the above
Explanation:-

56. Thermal relays are often used in

A. Generator protection
B. Transformer protection
C. Motor starters
D. None of the above

Answer : C. Motor starters
Explanation:-

57. Surge modifiers are used in

A. Reduce the current of wave front
B. Reduce the voltage wave front
C. Reduce the steepness of wave front
D. Modify the shape of wave front

Answer :C. Reduce the steepness of wave front
Explanation:-

58. Power transmitted will be maximum when

A. Sending end voltage is more
B. Receiving end voltage is more
C. Reactance is high
D. Corona losses are least

Answer :A. Sending end voltage is more
Explanation:-

59. Guard ring transmission line

A. Improves power factor
B. Reduces earth capacitance of the lowest unit
C. Reduces the transmission losses
D. Improves regulation

Answer : B. Reduces earth capacitance of the lowest unit
Explanation:-

60. Sinking fund is

A. Initial value-salvage voltage
B. Capital cost-operating cost
C. Periodic maintenance-breakdown maintenance
D. Capital cost/useful life

Answer : A. Initial value-salvage voltage
Explanation:-

61. First aid for electric shock victim is

A. Bandage
B. Massage
C. Pouring water on body
D. Artificial respirator

Answer :D. Artificial respirator
Explanation:-

62. HRC fuse provides best protection against

A. Short circuit
B. Iightening
C. Sparking
D. Fire

Answer : A. Short circuit
Explanation:-

63. In the circuit breaker the arcing contacts are made of

A. Electrolytic copper
B. Copper tungsten alloy
C. Aluminium alloy
D. Porcelain

Answer : B. Copper tungsten alloy
Explanation:-

64. Bulk oil circuit breaker is suitable for voltage upto

A. 10 kv
B. 16kv
C. 26kv
D. 36kv

Answer :D. 36kv
Explanation:-

65. Differential protection principle is used in the protection of

A. Generators
B. Transformers
C. Feeders
D. All of the above

Answer : D. All of the above
Explanation:-

66. Single core cables are usually not provided with

A. Sheath
B. Steel armouring
C. Rubber insulation
D. Paper insulation

Answer : D. Paper insulation
Explanation:-

67. When the diameter of the core cable is doubled, the value of capacitance

A. Will be reduced to one fourth
B. Will be reduced to half
C. Will be doubled
D. Will be comes four times

Answer : D. Will be comes four times
Explanation:-

68. The voltage of low tension cables is

A. Less than 220V
B. Less than 400V
C. Less than 600V
D. Less than 1000V

Answer : A. Less than 220V
Explanation:-

69. Impulse voltages are characterized by

A. Polarity
B. Peak value
C. Tome of half the peak value
D. All of the above

Answer :D. All of the above
Explanation:-

70. UJT when used for triggering an SCR, have wave form

A. Sine wave
B. Square wave
C. Saw tooth wave
D. Trapezoidal

Answer :D. Trapezoidal
Explanation:-

71. In a dc chopper per unit apple is maximum when duty cycle a is

A. 0.1
B. 0.3
C. 0.5
D. 0.7

Answer : C. 0.5
Explanation:-

72. The phenomena of ‘creeping’ occurs in

A. Ammeters
B. Voltmeters
C. Watt meters
D. Watt hour meter

Answer : D. Watt hour meter
Explanation:-

73. In a merger when not in operation, the needle shows a resistance of

A. 0 ohms
B. 100 ohms
C. 555 ohms
D. Infinity

Answer : D. Infinity
Explanation:-

74. In induction furnace the charge is heated by

A. Magneto striction
B. Magnetic hysteris
C. Eddy currents
D. None of the above

Answer : C. Eddy currents
Explanation:-

75. The thyristor is turned off when the anode current falls below

A. Forward current
B. Latching current
C. Holding current
D. Break over current

Answer :B. Latching current
Explanation:-

76. In a thyristor dv/dt protection is achieved through the use of

A. L cross thyristors
B. R cross thyristors
C. RC across thyristors
D. RL across thyristors

Answer : C. RC across thyristors
Explanation:-

77. Earth electrodes can be in the form of

A. Rods and pipes
B. Strips
C. Plates
D. Any of the above

Answer : D. Any of the above
Explanation:-

78. An inductor

A. Allows ac to pass but blocks dc
B. Allows dc to pass but blocks ac
C. Allows both ac and dc to pass
D. Blocks dc

Answer : C. Allows both ac and dc to pass
Explanation:-

79. In ac circuit the power is consumed only

A. Inductance
B. Capacitance
C. Resistance
D. All the given above

Answer : C. Resistance
Explanation:-

80. Which system has tendency to oscillate

A. Open loop system
B. Closed loop system
C. Both open loop and close loop systems
D. Neither open loop nor closed loop systems

Answer : B. Closed loop system
Explanation:-

81. The output of thermo couple is

A. DC current
B. AC current
C. DC voltage
D. AC voltage

Answer : C. DC voltage
Explanation:- Thermocouple is a device that is used to convert change in temperature into dc voltage

82. A two phase induction motor contains

A. Two stator windings
B. Two rotor windings
C. Both A and B
D. None of the above

Answer : A. Two stator windings
Explanation:-

83. The effect of moisture in the insulating material is

A. To increase insulating resistance
B. To increase dielectric strength
C. To increase dielectric loss
D. To decrease dielectric constant

Answer : C. To increase dielectric loss
Explanation:-

84. The permeability of soft iron can be increased by

A. Purifying it
B. Reducing carbon percentage
C. Alloying with cobalt
D. Increasing carbon percentage

Answer :C. Alloying with cobalt
Explanation:-

85. A region around a stationary electric charge has

A. Magnetic field
B. Electric field
C. Both magnetic and electric field
D. Neither magnetic nor electric field

Answer : B. Electric field
Explanation:-

86. When a dielectric is placed in an electric field the field strength

A. Increases
B. Decreases
C. Remains unchanged
D. Reduces to zero

Answer : B. Decreases
Explanation:-

87. Ferrites are a sub group of

A. Paramagnetic materials
B. Ferromagnetic materials
C. Ferrimagnetic materials
D. Non magnetic materials

Answer : C. Ferrimagnetic materials
Explanation:-

88. In order to minimize the loss due to hysteresis, the magnetic material should have

A. Low hysteresis co-efficient
B. High relentivity
C. High resistivity
D. Large B/H loop area

Answer : A. Low hysteresis co-efficient
Explanation:-

89. For dc voltage an inductor is virtually a

A. Short circuit
B. Open circuit
C. Depends on polarity
D. Depends on magnitude of voltage

Answer : A. Short circuit
Explanation:-

90. Ferri magnetic materials generally find application as

A. Conductors
B. Insulators
C. Super conductors
D. Semi conductors

Answer : D. Semi conductors
Explanation:-

91. Laplace transform of 1 is

A. Zero
B. 1
C. S
D. 1/S

Answer : D. 1/S
Explanation:-

92. The element of electric heater is made of

A. Copper
B. Steel
C. Carbon
D. Nichrome

Answer : D. Nichrome
Explanation:-

93. Current carrying capacity of a fuse material depends on

A. Cross sectional area
B. Length
C. Material
D. All of the above

Answer : D. All of the above
Explanation:-

94. Poor power factor results in all of the following except

A. Over loading of transformers
B. Over loading of alternators
C. Reduction in power losses
D. Reduction in load handling capacity of electrical systems

Answer : C. Reduction in power losses
Explanation:-

95. The electrode for a battery must be

A. A good conductor of electricity
B. A bad conductor of electricity
C. A semi conductor
D. An insulator

Answer : A. A good conductor of electricity
Explanation:-

96. Galvanizing is the coating of

A. Lead
B. Chromium
C. Brass
D. Zinc

Answer : D. Zinc
Explanation:-

97. For the same load, if the power factor of the load is reduced, it will

A. Draw more current
B. Less current
C. Same current but less power
D. Same current but more power

Answer :A. Draw more current
Explanation:-

98. In a series RC circuit as frequency increases

A. Current increases
B. Current decreases
C. Remains unaltered
D. None of the above

Answer : A. Current increases
Explanation:-

99. Super position theorem is applicable to

A. Current only
B. Voltage only
C. Both current and voltage
D. Current, voltage and power

Answer : D. Current, voltage and power
Explanation:-

100. Low frequency response of amplifier is mainly limited by

A. Input capacitor
B. By pass capacitor
C. Output capacitor
D. Biasing capacitor

Answer : B. By pass capacitor
Explanation:-