Question

1. Increasing the diameter of turbine blade 3 times power of turbine will 2. Maximum possible efficiency of a wind turbine i 3. A taller wind turbine gives higher power because at higher altitude A) Increase 2 times 1B) decrease 4 times C) incrense 8 times D) Increase 9 tinves As A)39% B) 49% C)50% D) 90% Ans A) Density of air is higher B) air velocity of higher C) air pressure is higher D) air temperature is higher Anst 4. Wind energy reduces global warming (CTrue/False) Ans: 5. The ratio of the actual area of the blades to the circular area they sweep out is called A) Solidarity B) Solid C) Solidity D) Saltity Ans: 6. HAWT is more common than VAWT (T/) Ans: 7. In a wind turbine with pitch control if the wind velocity goes beyond rated speed, the power will A) Increases B) decreases C) remains constant at rated power D) shut down Ans: A) Blade tip speed/wind speed B) wind specdЉ1ade speed C) wind speed/sound speed D) 8. Tip-speed ratio is blade speed/wind speed Ans: 9. Power from a wind turbine is proportional to A) density of air B) (Vclocity of wind)2 c) circular area swept by blades D) Height of the turbine Answer(o) : 10. For a given wind turbine if wind speed doubles, its power will A) Increase 2 times B) increase 4 times C) increase 8 times D) decrease 8 times Ans:

Answer 1

"tip -speed ratio is The ratio between The Tangential speed of The tip of a blade to actual speed of The wind tip speed ration = Blade tip speed/wind speed Power from a wind turbine is proportional to P = pi/8 rho A^2 v^3 p rho Power is proportional to density For a given wind turbine if wind speed double, its power will be increased 8 times because power is proportional to of velocity p_1 = pi/8 rho D^2 v^3 p_2 = pi/8 rho D^2 (2v)^3 p_1/p_2 = 1/8 therefore p_2 = 8p_1 In a wind turbine with pitch control if the wind velocity goes beyond noted speed, The power will be Remain constant at rated power The ratio of Actual area of the blades to the circular area they sweep out is called as ""solidity"" \r\n increasing The diameter of the turbine 3 time, power of wind Turbine will we know that P = 1/2 mv^2 = 1/2 rho "