Section: Fluid Mechanics | Marks: 2
Consider the following figures shown below. The objects are marked as A1, A2, B1, B2 and C1, C2 and the flow directions over these objects are shown by the respective arrow placed to the left of the object. Freestream velocities are same for all the cases. Amongst these objects, A1, A2, B1 and C1 are having smooth surfaces while B2 and C2 are having rough surfaces. Reynolds number is such that flow over rough surfaces become turbulent and flow over smooth surfaces can be considered laminar. All the airfoils can be considered as thin slender airfoil. Among the statements (i) to (vi) made about the drag of these objects which is/are correct? (i) Drag of object A1 is less than drag of object A2. (ii) Drag of Object A1 and A2 are same. (iii) Drag of Object B1 is more than drag of object B2. (iv) Drag of object B2 is more than drag of object B1. (v) Drag of Object C1 is more than drag of object C2. (vi) Drag of object C2 is more than drag of object C1.
- A. (i),(iii) & (vi)
- B. (ii),(iii) & (vi)
- C. (i),(iii) & (v)
- D. (i),(iv) & (vi)
Answer: A. (i),(iii) & (vi)