WIND POWER

Question 1

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 1

C. ALTERNATOR

Question 2

2. What component of force is used in multi-bladed windmills?

A. Lift force B. Drag force C. Side force D. Drop force

Answer 2

A. LIFT FORCE

Question 3

3. What component of force is used in savonius windmills?

A. Lift force B. Drag force C. Side force D. Drop force

Answer 3

B. DRAG FORCE

Question 4

4. The type of pump is appropriate for multi-bladed windmills.

A. Hydraulic B. Pneumatic C. Reciprocating D. Diaphragm

Answer 4

C. RECIPROCATING

Question 5

5. While the windmill is in operation, what efficiency can exceed 100%?

A. Volumetric B. Transmission C. Rotor D. All of the above

Answer 5

A. VOLUMETRIC

Question 6

6. 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 6

C. JET STREAM

Question 7

7. 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 7

A. HINGED SIDE VANE

Question 8

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 8

B. CONNECTING ROD

Question 9

In wind farm development, which should be done first?

A. Rotor
B. Energy demand survey
C. Transmission D. Wind velocity measurement

Answer 9

D. WIND VELOCITY MEASUREMENT

Question 10

In multi-bladed windpump manufacturing, which should be done first?

A. Rotor blade B. Rotor frame C. Tower D. Jig

Answer 10

D. JIG

Question 11

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 11

C. CRANK ARM

Question 12

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 12

B. 45

Question 13

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 13

D. 90-95%

Question 14

If a multi-bladed windpump has a tip-speed ratio of 1:1, what windspeed is needed to have its rotor tip move at
3.2 m/s?

A. 1 m/s
B. 3 m/s
C. 1 ft/s
D. 3 ft/s

Answer 14

B. 3 m/s
Windspeed = tip speed, since tip-speed ratio is 1:1
= 3.2 m/s