St. JOSEPH’S COLLEGE OF ENGINEERING
Chennai -600 119
Department of Electrical and Electronics
Engineering
EE6801 – Electric Energy Generation, Utilization
and Conservation
MCQ with answer
1. For given maximum axle load tractive efforts of AC. locomotive will be
(a) Less than that of D.C. locomotive
(b) More than that of D.C. locomotive
(c) Equal to that of D.C. locomotive
(d) None of the above
2. The consideration involved in the selection of the type of electric drive for a particular
application depends upon
(a) Speed control range and its nature
(b) Starting Nature
(c) Environmental condition
(d) All of the above
3. Series motor is not suited for traction duty due to which of the following account?
(a) Less current drain on the heavy load torque
(b) Current surges after temporary switching off supply
(c) Self relieving property
(d) Commutating property at heavy load
4. Which of the following happens in Kando system?
(a) Three phase A.C. is converted into D.C.
(b) Single phase A.C. is converted into D.C.
(c) Single phase supply is converted into three phase system
(d) None of the above
5. _______ locomotive has the highest operational availability.
(a) Electric
(b) Diesel
(c) Steam
(d) Petrol
6. Automatic signalling is used for which of the following trains?
(a) Mail and express trains
(b) Superfast trains
(c) Suburban and Urban electric trains
(d) All trains
7. The coasting retardation is around
(a) 0.16 km phps
(b) 1.6 km phps
(c) 16 km phps
(d) 40 km phps
8. The speed of a superfast train is
(a) 60 kmph
(b) 75 kmph
(c) 100 kmph
(d) More than 100 kmph
9. The horsepower of steam locomotives is
(a) Up to 1500
(b) 1500 to 2000
(c) 2000 to 3000
(d) 3000 to 4000
10. The friction at the track is proportional to
(a) 1/speed
(b) 1/(speed)2
(c) Speed
(d) None of the above
11. Suburban railways use
(a) 1500 V DC
(b) 440 V three phase AC
(c) 660 V three phase AC
(d) 3.3 kV three phase AC
12. Long distance railways use
(a) 200 V DC
(b) 25 kV Single phase AC
(c) 25 kV Two phase AC
(d) 25 kV Three phase AC.
13. A submarine while moving under water, is provided driving power through
(a) diesel engines
(b) steam turbine
(c) gas turbine
(d) batteries
14. Which locomotive has the highest operational availability
(a) Diesel
(b) Electric
(c) Steam
(d) All have same availability.
15. Which motor is used in tramways
(a) AC single phase capacitor start motor
(b) AC three phase motor
(c) DC series motor
(d) DC shunt motor.
16. A drive suitable for mines where explosive gas exist, is
(a) Diesel engine
(b) Steam engine
(c) Battery locomotive
(d) Any of the above.
17. In case of locomotives the tractive power is provided by
(a) single cylinder double acting steam engine
(b) double cylinder, single acting steam engine
(c) double cylinder, double acting steam engine
(d) single stage steam turbine
18. The wheels of a train, engine as well as bogies, are slightly tapered to
(a) reduce friction
(b) increase friction
(c) facilitate braking
(d) facilitate in taking turns
19. Overall efficiency of steam locomotive system is close to
(a) 5 to 10%
(b) 25 to 30%
(c) 55 to 60%
(d) 75 to 80%.
20. Which of the following braking systems on the locomotives is costly ?
(a) Regenerative braking on electric locomotives
(b) Vacuum braking on diesel locomotives
(c) Vacuum braking on steam locomotives
(d) All braking systems are equally costly
21. For given maximum axle load tractive efforts of AC. locomotive will be
(a) less than that of D.C. locomotive
(b) more than that of D.C. locomotive
(c) equal to that of D.C. locomotive
(d) none of the above
22. Quadrilateral speed-time curve pertains to which of the following services ?
(a) Main line service
(b) Urban service
(c) Sub-urban service
(d) Urban and sub-urban service
23. Co-efficient of adhesion is
(a) high in case of D.C. traction than in the case of AC. traction
(b) low in case of D.C. traction than in the case of AC. traction
(c) equal in both AC. and D.C. traction
(d) any of the above
24. Which of the following braking systems is used on steam locomotives ?
(a) Hydraulic system
(b) Pneumatic system
(c) Vacuum system
(d) None of the above
25. In case of ________ free running and coasting periods are generally long.
(a) main-line service
(b) urban service
(c) sub-urban service
(d) all of the above
26. The normal value of adhesion friction is
(a) 0.12
(b) 0.25
(c) 0.40
(d) 0.75
27. Which braking method can bring the locomotive to dead stop.
(a) Plugging braking
(b) Rheostatic braking
(c) Regenerative braking
(d) None of the above
28. The braking retardation is usually in the range
(a) 0.15 to 0.30 km phps
(b) 0.30 to 0.6 km phps
(c) 0.6 to 2.4 km phps
(d) 3 to 5 km phps
(e) 10 to 15 km phps
29. The voltage used for suburban trains in D.C. system is usually
(a) 12 V
(b) 24 V
(c) 220 V
(d) 600 to 750 V
30. What type electric drive is used in cranes?
(a) Multimotor
(b) Group.
(c) Individual.
(d) Both A and C
31. Colour of light depends up on
(a) Velocity of light
(b) frequency
(c) wave length
(d) both (b) and (c)
32. Luminous flux is
(a) The rate of energy radiation in the form light waves
(b) The part of light energy, radiated by Sun that is received on earth
(c) Measured in lux
33. Candle power is
(a) The luminous flux emitted by the source per unit solid angle
(b) The light radiating capacity of a source in a given direction
(c) The unit of Illumination.
34. The Illumination at surface due to a source of light placed at a distance ‘d’ from the
surface varies as
(a) 1/d2 (b) 1/d (c) d (d) d2
35. The Illumination at various points on a horizontal surface illuminated by the same
source varies as
(a) Cos 𝜃 (b) Cos 2 𝜃 (c) Cos 3 𝜽 (d) 1/ Cos 𝜃
36. A zero watt lamp consumes power of
(a) Zero Watt (b) 5-10 W (c) about 15W (d) about 25W
37. The safe operating temperature of a tungsten filament lamp is
(a) 1000 ° C (b) 2000 ° C (c) 3000 °C (d) 3500 °C
38. The output of a tungsten filament depends on
(a) Size of the shell (b) size of the lamp (c) temperature of the filament (d) all of
the above
39. Filament lamps normally operate at a power factor of
(a)0.5 lagging (b) 0.8 lagging (c) Unity (d) 0.85 leading
40. Which gas is sometimes used in filament lamps?
(a) Nitrogen (b) Carbon dioxide (c) Argon (d) Krypton
41. In filament lamps, coiled coil filaments are used in
(a) Coloured lamps (b) Gas filled lamps (c) Low wattage lamps (d) Higher wattage
lamps
42. The ignition voltage for a sodium lamp is about
(a) 100-125 V (b) 200-240 V (c) 300-400V (d) 400- 600V
43. The sodium vapour lamp
(a) Is only suitable for AC and so needs choke control
(b) Needs capacitor in its Auto transformer circuit to improve the power factor which
is very low (about 0.3 lagging)
(c) Comes upto its rate output in approximately 15 minutes
(d) All of the above
44. The luminous efficiency of sodium vapour lamps is
lumens
(a) 40 – 50 (b) 50 – 100 (c) 120 – 200 (d) 10 – 12
45. The luminous efficiency of high pressure mercury vapour lamps ranges from
lumens per watt .
(a) 30 to 40 (b) 60 to 100 (c) 100 to 150 (d) 250 to 400
46. Which of the following lamps is a cold cathode lamp ?
(a) Sodium vapour lamp (b) Neon lamp (c) Mercury vapour lamp (d) None of the
above
47. The electrons of Neon tube work at
(a) Very low temperature (b) Ordinary voltage (c) 2kv – 6 kv (d) 33kv
48. Which of the following is present inside the Fluorescent tube
(a) Helium and Oxygen (b) Argon and Neon (c) Argon and carbon dioxide (d) Mercury
vapour
49. The capacitor is connected across the fluorescent tube circuit in order to
(a) Eliminate the noise (b) limit the current (c) improve the power factor of the
tube circuit (d) all the above
50. In a fluorescent tube, a ballast resistance is connected in series with the choke
(a) When the tube is operated on DC supply
(b) When the tube is operated on AC supply
(c) To reduce radio interference
(d) To reduce stroboscopic effects
51. The flicker effects of the fluorescent lamps is more pronounced at
(a) Lower voltages
(b) Higher voltages
(c) Higher frequencies
(d) Lower frequencies.
52. A fluorescent tube can be operated on
(a) Both DC as well as AC
(b) AC only
(c) DC only
(d) Satisfactorily only on DC.
53. Blinking of a fluorescent tube may be on account of
(a) Low circuit voltage
(b) Loose contact
(c) Defective starter
(d) Any of the above.
54. The life of a fluorescent tube is affected by
(a) Low voltage
(b) High voltage
(c) Frequency of switching and blinking
(d) All of the above.
55. Floodlighting is not used for
(a) Industrial purposes
(b) Advertising purposes
(c) Aesthetic purposes
(d) Any of the above.
56. Total flux required in any lighting scheme depends inversely on
(a) Surface area
(b) Space- height ratio
(c) Illumination
(d) Coefficient of utilisation.
57. The illumination level on a surface is least affected by
(a) Candle power of light source
(b) Ambient temperature
(c) Type of reflector used
(d) Distance of the light source.
58. The illumination level in houses in the range of
(a) 20 – 50 lux
(b) 100-200 lux
(c) 300-500 lux
(d) 700 lux.
59. The depreciation factor depends upon
(a) Ageing of the lamp(s)
(b) Lamp cleaning schedule
(c) Type of work carried out at the premises
(d) All of the above.
60. The lamp is provided with a reflector in order to
(a) Avoid glare
(b) Provide better illumination
(c) Protect the lamp
(d) All of the above.
61. Heat Transfer by conduction will not take place when the
A. Two bodies are at the same temperatures
B. Bodies are kept in vaccum
C. Bodies are immersed in water
D. Bodies are exposed to thermal radiations
62. The highest value of thermal conductivity is
A. Aluminium
B. Brass
C. Copper
D. Iron
63. In the indirect resistance heating method, maximum heat transfer takes place by
A. Convection
B. Radiation
C. Conduction
D. All of the above
64. Direct Resistance heating is used in
A. Electrode Boiler
B. Salt-bath furnace
C. Resistance Welding
D. All of the above
65. In direct arc furnace which of the following is of high value?
A. Current
B. Voltage
C. Power Factor
D. All of the above
66. For arc heating, the electrodes used are made of
A. Copper
B. Graphite
C. Tungsten
D. Aluminium
67. In submerged arc furnaces the power is controlled by
A. Varying the spacing between the electrodes
B. Varying the voltage applied to the electrodes
C. Either (A) or (B)
D. Varying the arc length
68. Usually arc furnaces are
A. Cylindrical or Conical Shapes
B. Rectangular Shape
C. Spherical Shape
D. V-Shape
69. In induction heating
A. Heat is produced due to currents induced in the charge by electromagnetic action
B. The resistance of the charge must be low and voltage applied must be high in
order to produce sufficient heat
C. Magnetic materials can be easily treated in comparison to non-magnetic materials
D. All of the above
70. Induction heating takes place in
A. Insulating materials
B. Conducting and magnetic materials
C. Conducting but non-magnetic materials
D. Conducing materials may be magnetic or non-magnetic
71. In induction heating, which of the following is of high value
A. Frequency
B. Current
C. Voltage
D. Power factor
72. Induction heating is possible in case of
A. DC Supply only
B. AC Supply only
C. Ferrous Materials only
D. Non-Conducting materials only
73. Induction furnaces are used for
A. Heat treatment of castings
B. Heating of insulators
C. Melting of aluninium
D. All of the above
74. The advantages of coreless induction furnaces are
A. Low erection and operating cost, lower melting point and precise power control
B. Simple charging and pouring
C. Possibility of employing vacuum heating necessary for precious metal melting
D. All of the above
75. In dielectric heating current flows through
A. Air
B. Dielectric
C. Metallic conductor
D. Ionic discharge between dielectric medium and metallic conductor
76. Hysteresis loss and eddy current loss are used in
A. Resistance Heating
B. Dielectric Heating
C. Induction heating of Steel
D. Induction heating of Brass
77. Dielectric loss is proportional to
A. Frequency
B. (frequency)2
C. (frequency)3
D. (frequency)1/2
78. The power factor will be maximum in case of
A. Electric Arc Heating
B. Resistance Heating
C. Induction Heating
D. Dielectric Heating
79. During resistance welding heat produced at the join is proportional to
A. Current
B. Voltage
C. I2R
D. Volt-amperes
80. Resistance welding cannot be used for
A. Ferrous materials
B. Non-ferrous materials
C. Dielectric
D. Any of the above
81. Spot welding process basically depends on
A. Generation of heat
B. Application of forging pressure
C. Both (A) and (B)
D. All of the above
82. In flash-butt welding
A. No special preparation of the faces to be welded is necessary
B. Clean and pure weld is obtained
C. Power requirement is less
D. All of the above
83. Projection welding can be considered as a mass production form of
A. Seam welding
B. Spot welding
C. Upset welding
D. Flash welding
84. The tips of the electrodes, for spot welding are made of
A. Carbon
B. Copper alloy or pure copper
C. Mica
D. porcelain
85. The electric arc has
A. Linear resistance characteristic
B. Positive resistance characteristic
C. Negative resistance characteristic
D. Highly inductive characteristic
86. For electric arc welding dc supply is obtained from
A. Motor – generator set
B. AC rectified welding unit
C. Either from motor-generator set or ac rectified unit
D. None of the above
87. In arc welding, the length of arc depends on
A. Kind of electrode used its coating and its diameter
B. Magnitude of current used
C. Position of welding
D. All of the above
88. Carbon arc welding
A. Uses carbon or graphite rod as a negative electrode and work to be welded as a
positive
B. Cannot be done with ac supply
C. Is not suitable for vertical and overhead welding
D. All of the above
89. In carbon arc welding
A. Electrode is positive with respective to work in case of DC Supply
B. Electrode is Negative with respective to work in case of DC Supply
C. Electrode is connected to neutral in case of ac supply
D. None of the above
90. In atomic hydrogen welding the electrodes used are made of
A. Mild steel
B. Tungsten
C. Carbon
D. Graphite
91. Which of the following energy has the greatest potential among all the sources of
renewable energy?
a) Solar energy
b) Wind Energy
c) Thermal energy
d) Hydro-electrical energy
92. What is the rate of solar energy reaching the earth surface?
a) 1016W
b) 865W
c) 2854W
d) 1912W
93. What is total amount of solar energy received by earth and atmosphere?
a) 3.8 X 1024 J/year
b) 9.2 X 1024 J/year
c) 5.4 X 1024 J/year
d) 2.1 X 1024 J/year
94. In what form is solar energy is radiated from the sun?
a) Ultraviolet Radiation
b) Infrared radiation
c) Electromagnetic waves
d) Transverse waves
95. The scattered solar radiation is called ____________
a) Direct Radiation
b) Beam Radiation
c) Diffuse radiation
d) Infrared Radiation
96. Insolation is less ____________
a) when the sun is low
b) when the sun right above head
c) at night
d) at sun rise
97. The angle of deviation of the normal to the surface from the local meridian is called as
_________
a) Surface azimuth angle
b) Solar azimuth angle
c) Solar altitude
d) Hour angle
98. The time from sunrise to sunset is termed as _______________
a) Slope
b) Day length
c) Local solar time
d) Solar intensity
99. Instrument used to measure direct beam of solar irradiance is called ____________
a) Pyranometer
b) Net radiometer
c) Gardon gauge
d) Pyrheliometer
100. Absorption of Solar radiations at earth’s surface occur due to presence of
a) Ozone
b) Water vapours
c) Carbon di-oxide
d) All of the above
101. The value of Solar Constant is
a) 1347 W/m2
b) 1357 W/m2
c) 1367 W/m2
d) 1377 W/m2
102. The function of a solar collector is to convert.......
a)Solar Energy into Electricity
b)Solar Energy radiation
c)Solar Energy thermal energy
d)Solar Energy mechanical energy
103. The output of solar cell is of the order of........
(a) 1 W
(b) 5 W
(c) 10 W
(d) 20 W
104. Flat plate collector absorbs.......
(a) Direct radiation only
(b) Diffuse radiation only
(c) Direct and diffuse both
(d) All of the above
105. Temperature attained by a flat-plate collector is of the........
(a) Order of about 900C
(b) Range of 1000C to 1500C
(c) Above 1500C
(d) None of the above
106. A module in a solar panel refers to
(a) Series arrangement of solar cells.
(b) Parallel arrangement of solar cells.
(c) Series and parallel arrangement of solar cells.
(d) None of the above.
107. What is the maximum possible output of a solar array?
(a) 300 W/m2
(b) 100 W/m2
(c) 250 W/m2
(d) 500 W/m2
108. The current density of a photo voltaic cell ranges from
(a) 10 – 20 mA/cm2
(b) 40 – 50 mA/cm2
(c) 20 – 40 mA/cm2
(d) 60 – 100 mA/cm2
109. Temperature attained by cylindrical parabolic collector is of the order of
(a) 50 – 100 °C
(b) 100 – 150 °C
(c) 150 – 200 °C
(d) 200 – 300 °C
110. In a solar collector, why is the transparent cover provide for?
(a) Protect the collector from dust.
(b) Reduce the heat losses from collector beneath to atmosphere.
(c) Transmit solar radiation only
(d) All of the above.
111. Solar cells are made of:
(a) Aluminium
(b) Germanium
(c) Silicon
(d) Cadmium
112. The efficiency of solar cells is about:
(a) 25%
(b) 15%
(c) 40%
(d) 60%
113. The voltage of solar cells is:
(a) 0.5 to 1 V
(b) 1 to 2 V
(c) 2 to 3 V
(d) 4 to 5 V
114. The output of solar cells is of the order of:
(a) 0.5 watts
(b) 1.0 watts
(c) 5.0 watts
(d) 10 watts
115. Sun tracking system is required in the case of:
(a) Cylindrical and parabolic and paraboloid
(b) Flat plate collector
(c) Both (a) and (b)
(d) None of the above
116. Most of the solar radiation received on the earth surface is within the range of:
(a) 0.25 to 0.4 micron
(b) 0.4 to 0.8 microns
(c) 0.6 to 0.95 microns
(d) 0.1 to 0.25 microns
117. The efficiency of a flat-plate solar collector using water as a heat-exchange fluid is
largest at which of the following temperature for the absorber plate? Assume Ta =
250C.
(a) 400C
(b) 600C
(c) 800C
(d) 1000C
118. Sunlight at Earth's surface is around
(a) 0.6 to 0.10 percent ultraviolet
(b) 3 to 5 percent ultraviolet
(c) 0.3 to 0.8 percent ultraviolet
(d) 0.1 to 0.5 percent ultraviolet
119. Temperature on the sun is around ______________
(a) 575 – 600 KK
(b) 7550 – 8000 KK
(c) 4570 – 6000 KK
(d) 5750 – 6000 K
120. Which of the following type of collector is used for low-temperature systems?
(a) Line focusing parabolic collector
(b) Paraboloid dish collector
(c) Flat plate collector
(d) None of the above
121. What does Heating and cooling of the atmosphere generates?
a) Thermo line circulation
b) Radiation currents
c) Convection currents
d) Conduction currents
122. How much is the energy available in the winds over the earth surface is estimated to
be?
a) 2.9 X 120 MW
b) 1.6 X 107 MW
c) 1 MW
d) 5MW
123. How much wind power does India hold?
a) 20,000 MW
b) 12,000 MW
c) 140,000 MW
d) 5000 MW
124. What is the main source for the formation of wind?
a) Uneven land
b) Sun
c) Vegetation
d) Seasons
125. What type of energy is wind energy?
a) Renewable energy
b) Non-renewable energy
c) Conventional energy
d) Commercial energy
126. The amount of energy available in the wind at any instant is proportional to ___
of the wind speed.
(a) Square root power of two
(b) Square root power of three
(c) Square power
(d) Cube power
127. Winds having following speed are suitable to operate wind turbines.
(a) 5 – 25m/s
(b) 10 – 35m/s
(c) 20 – 45m/s
(d) 30 – 55m/s
128. The wind speed is measured using an instrument called
(a) Pyranometer
(b) Manometer
(c) Anemometer
(d) Wind vane
129. The rate of change of wind speed with height is called
(a) Wind shear
(b) Wind rose
(c) Wind solidity
(d) None of the above
130. At gradient height the shear force is
(a) Zero
(b) Minimum
(c) Maximum
(d) None of the above
131. The gradient height is about _____ m from the ground.
(a) 500
(b) 1000
(c) 1500
(d) 2000
132. The atmosphere with uniform wind speed is called the ____ atmosphere
(a) Plain
(b) Surface
(c) Free
(d) Shear
133. The Nacelle of windmill houses
(a) Gearbox
(b) Brakes
(c) Generator
(d) All of the above
134. In which of the following, does machine rotor drives through a step up gear box?
a) Horizontal axis with two aerodynamic blades
b) Horizontal axis propeller type wind mill
c) Horizontal axis multi bladed type wind mill
d) Sail type wind mill
135. The rotor blades are continuously flexed by unsteady aerodynamic gravitational and
inertia loads.
a) True
b) False
136. Which type of the following consists of single blade?
a) Horizontal axis with two aerodynamic blades
b) Horizontal axis propeller type wind mill
c) Horizontal axis multi bladed type wind mill
d) Sail type wind mill
137. What does TSR stand for in design consideration of wind mills?
a) Tip speed ratio
b) Torque-synchronous ratio
c) Tip suspension ratio
d) Temporary speed restriction
138. With upto how many propellers can windmills are built?
a) 4
b) 2
c) 7
d) 6
139. Turbines with how many propellers are used in order to avoid vibrations?
a) 1
b) 2
c) 3
d) 4
140. What type of cross sections does wind turbine blades have?
a) Penta hedral cross section
b) Air foiled type cross section
c) Radar cross section
d) Turbo cross section
141. Which part of the wind mill acts as a housing for the turbine?
a) Wind Vane
b) Shaft
c) Wind mill head
d) Turbine
142. A rotor installed in a fixed orientation with the swept area perpendicular to the pre
dominate wind direction is called ___________
a) Nacelle
b) Yaw fixed machines
c) Blades
d) Anemometer
143. How is the action of yaw controlled in small turbines?
a) Tail vane
b) Blades
c) Shaft
d) Yaw motor
144. Which part of the wind turbines senses wind speed, wind direction, shaft speed and
torque?
a) Turbine blade
b) Shaft
c) Rotor
d) Controller
145. On what does the selection of supporting structure depends?
a) Length of blades
b) Rotating capacity
c) Capacity of generator
d) Transmission systems
146. Determine the power in the wind if the wind speed is 20 m/s and blade length is 50 m.
The air density is ρ = 1.23 kg/m.
a) 15687 W
b) 77244 W
c) 38622 W
d) 25647 W
147. A wind turbine travels with the speed is 10 m/s and has a blade length of 20 m.
Determine wind power. The air density is ρ = 1.23 kg/m.
a) 772440 W
b) 687420 W
c) 587430 W
d) 698740 W
148. Why is wind turbine designed to stop operation at cut out velocity?
a) To protect wheel against damage
b) To make a quick stop in emergencies
c) To improve the efficiency
d) In order to adjust the blades to wind direction
149. The fraction of time during a given period that the turbine is actually on line is called?
a) Availability factor
b) Flat rating
c) Cut in velocity
d) Cut out velocity
150. Name the windmill which has four blades mounted on a central post.
a) Post mill
b) Smock mill
c) Tower mill
d) Fan mill