MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Aerodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Generation of lift over an airfoil and formation of starting vortex is correctly explained by which of these? |
| A. | Kutta-Joukowski Theorem |
| B. | Kutta Condition and Kelvin’s Theorem |
| C. | Kutta-Joukowski Theorem and Kelvin’s Theorem |
| D. | Kutta Condition and Helmholtz Theorem |
| Answer» C. Kutta-Joukowski Theorem and Kelvin’s Theorem | |
| 2. |
In reality, the starting vortex dies out. Why? |
| A. | Lift becomes zero |
| B. | At later times, Kelvin’s theorem is not applicable |
| C. | Due to Viscosity |
| D. | This assumption is wrong. Starting vortex never dies |
| Answer» D. This assumption is wrong. Starting vortex never dies | |
| 3. |
Which of these is a result of Kelvin’s Theorem is essentially? |
| A. | Frozen Vortex Lines |
| B. | Vorticity |
| C. | Circulation |
| D. | Lift |
| Answer» B. Vorticity | |
| 4. |
Generation of lift is accompanied by a starting vortex at the trailing edge. If the flow is inviscid, this will not happen. What reason can best describe this? |
| A. | There is no boundary layer formation, hence no vorticity |
| B. | Kutta Condition is enforced |
| C. | Kelvin’s Theorem is violated |
| D. | Starting Vortex dies off instantly |
| Answer» B. Kutta Condition is enforced | |
| 5. |
During the formation of starting vortex, for an airfoil starting from rest, which is the correct sequence of events? (TE: Trailing Edge) |
| A. | Velocity becomes infinite at the TE > Unstable vortex sheet formed due to very high vorticity > High velocity gradient formed at TE which is pushed downstream > Flow starts to curl at the TE > Unstable vortex sheet curls to form point vortex |
| B. | Velocity becomes infinite at the TE > High velocity gradient formed at TE which is pushed downstream > Unstable vortex sheet formed due to very high vorticity > Flow starts to curl at the TE > Unstable vortex sheet curls to form point vortex |
| C. | Velocity becomes infinite at the TE > Flow starts to curl at the TE > Unstable vortex sheet formed due to very high vorticity > Unstable vortex sheet curls to form point vortex > High velocity gradient formed at TE which is pushed downstream > |
| D. | Flow starts to curl at the TE > Velocity becomes infinite at the TE > High velocity gradient formed at TE which is pushed downstream > Unstable vortex sheet formed due to very high vorticity > Unstable vortex sheet curls to form point vortex |
| E. | Velocity becomes infinite at the TE > Unstable vortex sheet formed due to very high vorticity > High velocity gradient formed at TE which is pushed downstream > Flow starts to curl at the TE > Unstable vortex sheet curls to form point vortexb) Velocity becomes infinite at the TE > High velocity gradient formed at TE which is pushed downstream > Unstable vortex sheet formed due to very high vorticity > Flow starts to curl at the TE > Unstable vortex sheet curls to form point vortexc) Velocity becomes infinite at the TE > Flow starts to curl at the TE > Unstable vortex sheet formed due to very high vorticity > Unstable vortex sheet curls to form point vortex > High velocity gradient formed at TE which is pushed downstream >d) Flow starts to curl at the TE > Velocity becomes infinite at the TE > High velocity gradient formed at TE which is pushed downstream > Unstable vortex sheet formed due to very high vorticity > Unstable vortex sheet curls to form point vortex |
| Answer» E. Velocity becomes infinite at the TE > Unstable vortex sheet formed due to very high vorticity > High velocity gradient formed at TE which is pushed downstream > Flow starts to curl at the TE > Unstable vortex sheet curls to form point vortexb) Velocity becomes infinite at the TE > High velocity gradient formed at TE which is pushed downstream > Unstable vortex sheet formed due to very high vorticity > Flow starts to curl at the TE > Unstable vortex sheet curls to form point vortexc) Velocity becomes infinite at the TE > Flow starts to curl at the TE > Unstable vortex sheet formed due to very high vorticity > Unstable vortex sheet curls to form point vortex > High velocity gradient formed at TE which is pushed downstream >d) Flow starts to curl at the TE > Velocity becomes infinite at the TE > High velocity gradient formed at TE which is pushed downstream > Unstable vortex sheet formed due to very high vorticity > Unstable vortex sheet curls to form point vortex | |
| 6. |
For a fluid initially at rest, the formation of starting vortex implies ______ |
| A. | generation of lift |
| B. | generation of circulation |
| C. | generation of lift and circulation |
| D. | no lift is produced |
| Answer» D. no lift is produced | |
| 7. |
A vortex sheet in the incompressible, inviscid fluid dies after some time. |
| A. | True |
| B. | False |
| Answer» C. | |
| 8. |
Which type of the following flow is characterized by density being a single-valued function of pressure only? |
| A. | Viscous Flow |
| B. | Barotropic Flow |
| C. | Inviscid Flow |
| D. | Baroclinic Flow |
| Answer» C. Inviscid Flow | |
| 9. |
For which of the following Kelvin’s theorem is applicable? |
| A. | Flow with Viscous Stresses |
| B. | Compressible Flow |
| C. | Inviscid, Compressible Barotropic Flow |
| D. | Flow with Non-Conservative Body Forces |
| Answer» D. Flow with Non-Conservative Body Forces | |
| 10. |
Mathematically, what is meant by Kelvin’s Circulation Theorem for an inviscid and incompressible flow? (For the same set of fluid elements moving in a closed curve along with the fluid). |
| A. | DΓ/Dt = 0 |
| B. | γ1 ≥ Γ2, where 1 is the upstream direction |
| C. | Γ = -∮C1V.ds |
| D. | .a) DΓ/Dt = 0b) γ1 ≥ Γ2, where 1 is the upstream directionc) Γ = -∮C1V.dsd) Γ = 0 |
| Answer» B. γ1 ≥ Γ2, where 1 is the upstream direction | |
| 11. |
For an arbitrary inviscid and incompressible flow, with all the body forces zero, what is best described by the given sketch? |
| A. | Boundary Layer Formation |
| B. | Kelvin’s Circulation Theorem |
| C. | Kutta Condition |
| D. | Generation of Lift |
| Answer» C. Kutta Condition | |
| 12. |
It is possible to have lift without friction (i.e. in an inviscid medium). |
| A. | True |
| B. | False |
| Answer» C. | |
| 13. |
Which of the following ensures flow smoothly leaving the trailing edge given the right value of circulation? |
| A. | Kutta Condition |
| B. | Momentum Theorem |
| C. | Angle of Attack |
| D. | The Shape of the Airfoil |
| Answer» B. Momentum Theorem | |