MCQOPTIONS
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MCQOPTIONS
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Aerodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
All bodies have skin-friction contribution more than that from the pressure drag. |
| A. | False |
| B. | True |
| Answer» B. True | |
| 2. |
Which of the following gives a better approximate distribution of drag over thin airfoils?The given percentages are for skin- friction drag and pressure drag respectively. |
| A. | 85, 15 |
| B. | 50, 50 |
| C. | 64, 35 |
| D. | Inadequate data |
| Answer» B. 50, 50 | |
| 3. |
For the boundary layer profile given below, select the regions which best represents where the transition in flow is taking place and mark the leading edge (respectively). |
| A. | i, ii |
| B. | ii, i |
| C. | iii, ii |
| D. | iv, ii |
| Answer» C. iii, ii | |
| 4. |
The phenomena best represented by the profile given in the following figure is_____ |
| A. | Shock waves |
| B. | Boundary layer |
| C. | Pressure distribution |
| D. | Variation of velocity |
| Answer» C. Pressure distribution | |
| 5. |
When the free-stream velocity is made one-third, the transition point moves downstream.The given statement is true or false? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
The transition point for a flow can be found using____ |
| A. | Average of Reynolds numbers at leading and trailing edges |
| B. | It is always the mid-chord |
| C. | Hit and trial methods |
| D. | Critical Reynolds number |
| Answer» E. | |
| 7. |
For a real flow over an airfoil, with Reynolds number in the laminar region as it starts, select the incorrect choice. |
| A. | Flow at trailing edge is laminar |
| B. | Flow is both turbulent and laminar at different places |
| C. | There is a transition region between leading and trailing edge |
| D. | Flow at trailing edge is turbulent |
| Answer» B. Flow is both turbulent and laminar at different places | |
| 8. |
The skin-friction coefficient for turbulent flow Cf is proportional to Rec. The proportionality constant is_____ |
| A. | 0.074 |
| B. | 0.64 |
| C. | 0.33 |
| D. | 1.328 |
| Answer» B. 0.64 | |
| 9. |
A given flow can be laminar all over an airfoil in a real case. Select the correct statement for the assumption given above. |
| A. | Always true |
| B. | Always false |
| C. | True only for symmetric airfoils |
| D. | Depends on the Reynolds number |
| Answer» C. True only for symmetric airfoils | |
| 10. |
The boundary layer thickness for turbulent flow at a distance x with Reynolds number Rex is δ. Which is____ |
| A. | Directly proportional to \(\sqrt[5]{x}\) |
| B. | Inversely proportional to \(\sqrt[5]{Re_x}\) |
| C. | Directly proportional to Rex |
| D. | Inversely proportional to x |
| Answer» C. Directly proportional to Rex | |
| 11. |
For a Reynolds number Rec=10×105 and chord length 1m, what is the turbulent boundary layer thickness at the trailing edge (in cm)? |
| A. | 0.0216 |
| B. | 0.037 |
| C. | 2.16 |
| D. | 0.37 |
| Answer» D. 0.37 | |
| 12. |
The skin-friction drag coefficient for turbulent flow on the bottom surface of an airfoil, with chord length being 1m is _____ (Reynolds number at the trailing edge Rec=32×105) |
| A. | 0.074 |
| B. | 0.0037 |
| C. | 0.027 |
| D. | 0.0074 |
| Answer» C. 0.027 | |
| 13. |
An exact analytical solution exists for turbulent flows also like laminar flow over airfoils. |
| A. | False |
| B. | True |
| Answer» B. True | |
| 14. |
For the same angle of attack and chord length, the boundary layer is thicker in_____ |
| A. | Turbulent flows |
| B. | Laminar flows |
| C. | Will be equal in both the flows |
| D. | Depends on the velocity of flow |
| Answer» B. Laminar flows | |