

MCQOPTIONS
Saved Bookmarks
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Aerodynamics knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which drag is prominent after exceeding the critical Mach number? |
A. | Form drag |
B. | Wave drag |
C. | Pressure drag |
D. | Skin – friction drag |
Answer» D. Skin – friction drag | |
2. |
What happens to the flow around the airfoil at upper critical Mach number? |
A. | The flow around airfoil becomes subsonic |
B. | The flow around airfoil becomes supersonic |
C. | The flow around airfoil becomes sonic |
D. | The flow around airfoil becomes hypersonic |
Answer» C. The flow around airfoil becomes sonic | |
3. |
Which equation is used to compute the critical Mach number of the airfoil? |
A. | (Cp)crit = \(\frac {2}{γM_{crit}^{2}} \bigg [ \frac {1 + \frac {1}{2}(γ – 1)M_{crit}^{2}}{1 + \frac {1}{2}(γ – 1)} \bigg ]^{\frac {γ}{γ – 1}}\) – 1 |
B. | (Cp)crit = \(\frac {2}{γM_{crit}^{2}} \bigg [ \frac {1 + \frac {1}{2}(γ – 1)M_{crit}^{2}}{1 + \frac {1}{2}(γ – 1)} \bigg ]^{\frac {γ}{γ + 1}}\) + 1 |
C. | (Cp)crit = γM\(_{crit}^{2} \bigg [ \frac {1 + \frac {1}{2}(γ – 1)}{1 + \frac {1}{2}(γ – 1)} \bigg ]^{\frac {γ}{γ – 1}}\) – 1 |
D. | (Cp)crit = γM\(_{crit}^{2} \bigg [ \frac {1 + \frac {1}{2}(γ – 1)}{1 + \frac {1}{2}(γ – 1)M_{crit}^{2}} \bigg ]^{\frac {γ}{γ – 1}}\) – 1 |
Answer» B. (Cp)crit = \(\frac {2}{γM_{crit}^{2}} \bigg [ \frac {1 + \frac {1}{2}(γ – 1)M_{crit}^{2}}{1 + \frac {1}{2}(γ – 1)} \bigg ]^{\frac {γ}{γ + 1}}\) + 1 | |
4. |
Which of these techniques is employed to delay the critical Mach number? |
A. | Increasing the thickness of airfoil |
B. | Swept wing |
C. | Increase camber |
D. | Decrease drag – divergence Mach number |
Answer» C. Increase camber | |
5. |
What is the relation between the drag divergence Mach number and critical Mach number? |
A. | Mdrag – divergence = Mcrit |
B. | Mdrag – divergence > Mcrit |
C. | Mdrag – divergence < Mcrit |
D. | Mdrag – divergence × Mcrit = 0 |
Answer» C. Mdrag – divergence < Mcrit | |
6. |
Thicker the airfoil, higher is the critical Mach number. |
A. | True |
B. | False |
Answer» C. | |
7. |
What is the coefficient of pressure at minimum pressure point a function of? |
A. | Critical Mach number |
B. | Freestream Mach number |
C. | Chord/thickness ratio of airfoil |
D. | Length of the airfoil |
Answer» B. Freestream Mach number | |
8. |
What is the coefficient of pressure at the minimum pressure point for an airfoil with critical Mach number as 0.6? |
A. | 1.53 |
B. | 1.66 |
C. | 1.42 |
D. | 1.15 |
Answer» C. 1.42 | |
9. |
The local Mach number at a point on the airfoil reaches 1 for critical Mach number. |
A. | True |
B. | False |
Answer» B. False | |
10. |
What is a critical Mach number? |
A. | Freestream Mach number for which stagnation pressure is obtained |
B. | Freestream Mach number for which sonic flow is obtained |
C. | Free stream Mach number for which supersonic flow is obtained |
D. | Freestream Mach number for which hypersonic flow is obtained |
Answer» C. Free stream Mach number for which supersonic flow is obtained | |