Engineering Questions with Answers - Multiple Choice Questions
Aerodynamics – The Cambered Airfoil – 1
1 - Question
Is camber is the asymmetry between the two acting surfaces of an airfoil?
a) True
b) False
View Answer
Explanation: Camber is the asymmetry between the two acting surfaces of an airfoil, with the top surface of a wing or corresponding the front surface of a propeller blade, commonly being more convex, positive camber.
2 - Question
Is airfoil with high camber produce the maximum lift?
a) False
b) True
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Explanation: Camber is usually designed into an airfoil is to increase the maximum lift coefficient. This minimizes the stalling speed of aircraft using airfoil. Aircraft with wings based on cambered airfoils usually have low lower stalling speeds than similar aircraft with wings based on symmetric airfoils.
3 - Question
How to increase the critical angle of attack?
a) Reduce the camber
b) Increase the camber
c) Increase the thickness
d) Reduce the thickness
View Answer
Explanation: An aircraft designer may also reduce the camber of the outboard section of the wings to increase the critical angle of attack at the wing tips. When the wing approaches the stall angle this will ensure that the wing root stalls before the tip, giving the aircraft resistance to spinning and maintaining ailerons effectiveness close to the stall.
4 - Question
Is supersonic flight uses supercritical airfoil?
a) True
b) False
View Answer
Explanation: To do different types of maneuvers at a speed Mach greater than 1. So, the designers use negative camber airfoil this is called super critical airfoil. It is used for near supersonic flight and produces high lift to drag ratio at near supersonic flight than a traditional airfoil.
5 - Question
Is supercritical airfoil has flattened upper surface?
a) True
b) False
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Explanation: Supercritical airfoil employ a flattened upper surface, highly cambered after section and greater leading edge radius as compared to traditional airfoil shapes. These changes delay the onset of the wave drag.
6 - Question
Is positive camber upper surface is more convex?
a) True
b) False
View Answer
Explanation: An airfoil is said to have positive camber if, as is commonly the case, its upper surface or in the case of a propeller or turbine blade its forward surface is more convex. But camber is a complex property that can be fully characterized by an airfoil camber line.
7 - Question
What is reflexed camber airfoil?
a) Camber line curves backup near the trailing edge
b) Chord line curves backup near the trailing edge
c) Camber and chord are at stationary
d) Chord is at stationary
View Answer
Explanation: An airfoil where the camber line curves back up near the trailing edge is called a reflexed camber airfoil. Such an airfoil is useful in certain situations, such as with tailless aircraft, because the moment about the aerodynamic center of the airfoil is zero.
8 - Question
Is camber is the curve of the upper and lower surfaces of an airfoil?
a) True
b) False
View Answer
Explanation: The camber is the curve of the upper and lower surfaces of an airfoil. This curve is measured by how much it departs from the chord of the airfoil, the horizontal line joining the leading and trailing edges, some airfoil has a high degree of camber.
9 - Question
Is upper camber refers to the camber of the upper surface?
a) True
b) False
View Answer
Explanation: The term upper camber refers to the camber of the upper surface of the airfoil. The term lower surface refers to the lower surface of the airfoil. When the curve is away from the chord, the camber is said to be positive.
10 - Question
Is camber of an airfoil causes an increase in velocity?
a) True
b) False
View Answer
Explanation: The camber of an airfoil causes an increase in velocity and a consequent decrease in pressure of the stream of air moving over it due to the increase in velocity it gets a maximum coefficient of lift. Hence it is used in military aircraft.