POWER PLANT MCQ PART 10

13-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

Ans A

 

14-At gradient height the shear force is

(A) Zero

(B) Minimum

(C) Maximum

(D) None of the above

 Ans A

 

15-The gradient height is about _____ m from the ground.

(A) 500

(B) 1000

(C) 1500

(D) 2000

 Ans D

 

16-The atmosphere with uniform wind speed is called the ____ atmosphere

(A) Plain

(B) Surface

(C) Free

(D) Shear

 Ans C

 

17-Surface layer is the air layer considered from the height of local obstruction to a height of about

(A) 50m

(B) 100m

(C) 150m

(D) 200m

 Ans B

 

18-Air layer from 100m that extends up to the gradient height is known as

(A) Surface layer

(B) Ekman layer

(C) Boundary layer

(D) None of the above

Ans B

 

19-Low solidity rotors use which of the following force for rotation

(A) Drag

(B) Lift

(C) Centrifugal

(D) Centripetal

Ans B

 

20-The following is the tangential velocity of the blade due to the rotation of blade.

(A) Wind velocity

(B) Incident wind velocity

(C) Blade linear velocity

(D) Relative velocity

Ans C

 

21-Turbines blades have ____ type cross section to extract energy from wind.

(A) Aerofoil

(B) Elliptical

(C) Rectangular

(D) All of the above

Ans A

 

22-The Nacelle of windmill houses

(A) Gearbox

(B) Brakes

(C) Generator

(D) All of the above

Ans D