MCQ Questions on Wind Energy Sources

 

1.     How much power does the small scale wind machine generate?
a) 18 KW
b) 2 KW
c) 12 KW
d) 30 KW

Answer: b
Explanation: These might be used on farms remote applications and other places requiring relatively low power. The generating capacity is up to 2kW. Small scale wind machines lower your electricity bills by 50% – 90%.

2.     Which type of wind machines are used at several residence or local use?
a) Large size machines
b) Remote machines
c) Small size machines
d) Medium size machines

Answer: d
Explanation: These wind turbines may be used to supply less than 100 kW rated capacity, to several residences or local use. These do not require much space they can be installed on roof tops or on some high elevated areas.

3.     Which type of wind turbines produce 100 kW or greater?
a) Large machines
b) Small machines
c) Medium machines
d) Remote Machines

Answer: a
Explanation: Large wind turbines are those of 100 kW rated capacity or greater. They are used to generate power for distribution in central power grids. They can have single generator at a single site or multiple generators sited at several places over an area.

4.     Which part of the wind mill acts as a housing for the turbine?
a) Wind Vane
b) Shaft
c) Wind mill head
d) Turbine

Answer: c
Explanation: The wind mill head supports the rotor, housing, and rotor bearings. It also has control mechanism like changing the pitch of the blades for safety devices, tail vane to orient the rotor to face the wind. Its body is the size of the mini bus.

5.     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

Answer: b
Explanation: In the locations with the prevailing wind in one direction, the design of a turbine can be greatly simplified. The rotor can be installed in a fixed orientation with the swept area perpendicular to the pre dominate wind direction. This machine is called yaw fixed.

6.     How is the action of yaw controlled in small turbines?
a) Tail vane
b) Blades
c) Shaft
d) Yaw motor

Answer: a
Explanation: In small turbines, yaw action is controlled by a tail vane while is larger machines a servomechanism operated by a wind-direction sensor controls the yaw motor keeping the turbine properly oriented.

7.     Which part of the wind turbines senses wind speed, wind direction, shaft speed and torque?
a) Turbine blade
b) Shaft
c) Rotor
d) Controller

Answer: d
Explanation: The controller senses wind speed, wind direction, shafts speeds and torques, output power and generator temperature, Control signals are generated with the electrical output corresponding to the wind energy input.

8.     Which type of wind turbine has low RPM?
a) Small wind turbine
b) Large wind turbine
c) Medium wind turbine
d) Remote wind turbine

Answer: b
Explanation: The rate of rotation of large wind turbine generators operating at rated capacity or below is controlled by varying the pitch of the rotor blades. It has low rpm, about 40 to 50. It is necessary to increase greatly the low rotor rate of turning using transmission mechanism.

9.     Why recommendation of fixed ratio gears done for top mounted equipment?
a) Because they are easy install
b) Requires less space
c) Due to its low cost
d) Because of their high efficiency

Answer: d
Explanation: Fixed ratio gears are recommended for top mounted equipment because of their high efficiency, and minimum system risk. For bottom mounted equipment requiring a right angle drive transmission costs can be reduced on the hub by increasing rotor speed to generator.

10.    Which type of generator are made use in wind turbines?
a) Recreational generators
b) Synchronous generator
c) Asynchronous generator
d) Alternator

Answer: b
Explanation: Generators may be either constant or variable speed type. Variable speed units are expensive and/or unproved. Constant speed generator in use are synchronous induction and permanent magnet types. Synchronous unit is used for large aero generator systems. It is very versatile and has an extensive data base.

11.     In which part do we find sensors and actuators?
a) Fixed gears
b) Turbines
c) Control systems
d) Blades

Answer: c
Explanation: Control systems involves sensors and actuators. The modern large wind turbine generator requires a versatile and reliable control system. A control system is used for i) changing the orientation of the rotor into the wind. ii) Start up and cut-in of the equipment. iii) Power control of the rotor by varying the pitch of the blades.

12.    How many types of supporting tower for wind mill are generally used?
a) 2
b) 4
c) 3
d) 5

Answer: b
Explanation: Four types of generating tower are used generally:
i) The reinforced concrete tower
ii) The pole tower
iii) The built up shell tube tower
iv) The truss tower.

13.   On what does the selection of supporting structure depends?
a) Length of blades
b) Rotating capacity
c) Capacity of generator
d) Transmission systems

Answer: d
Explanation: The type of the supporting structure and its height is related to cost and the transmission system incorporated. Horizontal axis wind turbines are mounted on towers so as to be above the level of turbulence and other ground related effects.

14.    At what type of location vibrations are more in the wind turbine?
a) Downwind location
b) Up wind location
c) Windward
d) Leeward

Answer: b
Explanation: In the upwind location (i.e. the wind encounters the turbine before reaching the tower), the wake of the passing rotor blades causes repeated changes in the wind forces on the wind forces on the tower. Due to this the tower may vibrate and may eventually be damaged.

15.    At what type of location vibrations are less in the wind turbines?
a) Windward
b) Leeward
c) Downwind location
d) Upwind Location

Answer: c
Explanation: If the turbine is downwind from the tower, vibrations are less but the blades are subjected to severe alternating forces as they pass through the tower wake. Downwind rotors are generally preferred for large aero generators.

16.      What does Heating and cooling of the atmosphere generates?
a) Thermo line circulation
b) Radiation currents
c) Convection currents
d) Conduction currents

Answer:  c
Explanation: Wind energy can be economically used for the generation of electrical energy. Heating and cooling of the atmosphere generates convection currents. Heating is caused by the absorption of solar energy on the earth surface.

17.     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

Answer: b
Explanation: The energy available in the winds over the earth surface is estimated to be 1.6 X 107 MW which is almost the same as the present day energy consumption. Wind energy can be utilized to run wind mill which in turn, is used to drive the generators.

18.    How much wind power does India hold?
a) 20,000 MW
b) 12,000 MW
c) 140,000 MW
d) 5000 MW

Answer: a
Explanation: India has a potential of 20,000 MW of wind power. Wind power accounts nearly 9.87% of India’s total installed power generation capacity. Generation of wind power in India mainly account from southern state of India.

19.      What is the main source for the formation of wind?
a) Uneven land
b) Sun
c) Vegetation
d) Seasons

Answer: b
Explanation: Wind is free and renewable form of energy, which throughout history has been used to grind grain, power ships, and pump water. Wind is created when the sun unevenly heat the earth surface.

20.   Which country created wind mills?
a) Egypt
b) Mongolia
c) Iran
d) Japan

Answer: c
Explanation: The earliest known wind mills were in Persia (Iran). These early wind mills looked like large paddle wheels. Centuries later, the people of Holland improved the basic design of wind mill. Holland is famous for its wind mills.

21.    “During the day, the air above the land heats up more quickly than the air over water”.
a) True
b) False

Answer: a
Explanation: During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and raises, and the heavier, cooler air rushes in to take its place, creating winds.

22.      What happens when the land near the earth’s equator is heated?
a) All the oceans gets heated up
b) Small wind currents are formed
c) Rise in tides
d) Large atmospheric winds are created

Answer: d
Explanation: The large atmospheric winds that circle the earth are created because the land near the earth’s equator is heated more by the sun than the land near the north and south poles. Wind energy is mainly used to generate electricity.

23.  What type of energy is wind energy?
a) Renewable energy
b) Non-renewable energy
c) Conventional energy
d) Commercial energy

Answer: a
Explanation: Wind is called a renewable energy source because the wind will blow as long as the shines. Wind power, as an alternative to burning fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, consumes no water, and uses little land.

24.  What are used to turn wind energy into electrical energy?
a) Turbine
b) Generators
c) Yaw motor
d) Blades
Answer: a
Explanation: Wind turbine blades capture wind energy, a form of mechanical energy, and put it to work turning a drive shaft, gearbox, and generator to produce electrical energy. Many factors affects wind turbine efficiency including turbine blade aerodynamics.

25.   What is the diameter of wind turbine blades?
a) 320 feet
b) 220 feet
c) 80 feet
d) 500 feet
Answer: b
Explanation: Large utility-scale wind turbines can now generate more than a MW of electrical power each and deliver electricity directly in to the electric grid, these turbines are placed at 200 feet height at the rotor hub and have blades which are 220 feet or more in diameter.

26.  At what range of speed is the electricity from the wind turbine is generated?
a) 100 – 125 mph
b) 450 – 650 mph
c) 250 – 450 mph
d) 30-35 mph
Answer: d
Explanation: Wind turbines are designed with cut-in wind speeds and cut-out speeds i.e. the wind speeds when the turbines start turning or shut off to prevent drive train damage. Typically, maximum electric generations occurs at speeds of 30-35mph.

27.      When did the development of wind power in India began?
a) 1965
b) 1954
c) 1990
d) 1985
Answer: c
Explanation: The development of wind power in India began in 1990s. Presently India is the world’s fourth largest wind power generator. The Indian energy sector has an installed capacity of 32.72 GW. Today India is a major player in the global wind energy market.