Now, you can derive this a is V 1 by V A. We have got V 1 and thrust equation we have given. So, if you use all those values that are given, you can show that efficiency can also be represented in terms of thrust loading coefficient. What are the inferences we are getting from this representation of efficiency? We can derive very interesting observation from here. Whenever we are talking of designing a propeller, we are interested in having a highly efficient propeller. Is not it? We want to increase efficiency.