- In an aerogenerator exceeding 100 kw capacity, which part is responsible in converting rotational movement to
electricity?
A. Rotor
B. Turbine
C. Alternator
D. Governor
Answer: C
- What component of force is used in multi-bladed windmills?
A. Lift force
B. Drag force
C. Side force
D. Drop force
Answer: A
- What component of force is used in savonius windmills?
A. Lift force
B. Drag force
C. Side force
D. Drop force
Answer: B
- The type of pump is appropriate for multi-bladed windmills.
A. Hydraulic
B. Pneumatic
C. Reciprocating
D. Diaphragm
Answer: C
- While the windmill is in operation, what efficiency can exceed 100%?
A. Volumetric
B. Transmission
C. Rotor
D. All of the above
Answer: A
- What wind energy resource is located about 10-16 km from Earth surface with velocity over 150 kph?
A. Terrestrial wind
B. Extra-terrestrial wind
C. Jet stream
D. High wind
Answer: C
- In multi-bladed windpumps, which part is responsible in converting rotational movement to reciprocating action?
A. Rotor
B. Connecting rod
C. Reciprocating pump
D. Crank arm
Answer: B
- What tail type of multi-bladed windpump is more effective for windy areas?
A. Hinged side vane
B. Ecliptic
C. Manual folding
D. No tail
Answer: A
MODERATE QUESTIONS:
1. In wind farm development, which should be done first?
A. Rotor
B. Energy demand survey
C. Transmission
D. Wind velocity measurement
Answer: D
- In multi-bladed windpump manufacturing, which should be done first?
A. Rotor blade
B. Rotor frame
C. Tower
D. Jig
Answer: D
- To have bigger water displacement volume in windpumps, which should be increased?
A. Connecting rod length
B. Rotor diameter
C. Crank arm
D. Well diameter
Answer: C
- In windmill design, what should be the average rotor blade twist angle in degrees to have a tip speed ratio of 1:1?
A. 30
B. 45
C. 60
D. 75
Answer: B
- If typical overall efficiency of savonius windmills is 7-10%, what is the typical overall efficiency of aerogenerators?
A. 7-10%
B. 15-17%
C. 18-21%
D. 90-95%
Answer: D
- If a multi-bladed windpump has a tip-speed ratio of 1:1, what windspeed is needed to have its rotor tip move at
- 2 m/s?
A. 1 m/s
B. 3 m/s
C. 1 ft/s
D. 3 ft/s
Answer: B
Solution:
Windspeed = tip speed, since tip-speed ratio is 1:1
= 3.2 m/s
