Given below are two statements, one is labelled as Assertion (A) and the other…
2020
Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): A windmill with proper design considerations can be made to operate at efficiencies in the range 60% to 65%.
Reason (R): The efficiency of the windmill depends on its design parameters.
In light of the above statements, choose the most appropriate answer from the options given below:
- A.
Both A and R are correct and R is the correct explanation of A
- B.
Both A and R are correct but R is NOT the correct explanation of A
- C.
A is correct but R is not correct
- D.
A is not correct but R is correct
Show answer & explanation
Correct answer: D
For wind turbines/windmills, Betz law gives a theoretical maximum power coefficient of about 59.3% for extracting kinetic energy from wind. Therefore, the assertion that a properly designed windmill can operate at 60% to 65% efficiency is not correct. However, the reason is correct because actual windmill efficiency depends on design parameters such as rotor/blade design, losses and operating conditions. Hence, Assertion (A) is not correct but Reason (R) is correct.