- For a fixed center of gravity location of an airplane, when the propeller is mounted on the nose of the fuselage
- longitudinal static stability increases
- longitudinal static stability decreases
- longitudinal static stability remains same
- longitudinal static stability is maximum

Answer:-

- Let an airplane in a steady level flight be trimmed at a certain speed. A level and steady flight at higher speed could be achieved by changing
- engine throttle only
- elevator only
- throttle and elevator together
- rudder only

Answer:- elevator only

The elevator can be used to change and control the trim of the airplane. In essence, this controls the equilibrium velocity of the airplane. For example, by a downward deflection of the elevator, a new trim angle smaller than the original trim angle can be obtained. this corresponds to an increase in velocity of the airplane. - For a plane strain problem in the x-y plane, in general, the non-zero stress terms are
- σ
_{zz}, σ_{xz}, σ_{yz}, σ_{xy} - σ
_{zz}, σ_{xz}, σ_{yz}, σ_{xy} - σ
_{xx}, σ_{xy}, σ_{yy}, σ_{xz} - σ
_{xx}, σ_{yy}, σ_{xy}, σ_{zz}

Answer:-

- σ
- For an elastic anisotropic solid, the number of independent elastic constants in its consitutive equations is
- 2
- 9
- 21
- 36

Answer:-

- Total pressure at a point is defined as the pressure when the flow is brought to rest
- adiabatically
- isentropically
- isothermally
- isobarically

Answer:- isentropically

Adiabtic means No heat transfer

Isentropic means reversible adiabatic

Isothermal means COnstant temperature

Isobaric means constant pressure - The drag divergence Mach number of an airfoil
- is a fixed number for a given airfoil
- is always higher than the critical Mach number
- is equal to the critical Mach number at zero angle of attack
- is the Mach number at which a shock wave first appears on the airfoil

Answer:- is always higher than the critical Mach number

- On which one of the following thermodynamic cycles does an ideal ramjet operate?
- The Rankine cycle
- The Brayton cycle
- The Carnot cycle
- The Otto cycle

Answer:- The Brayton cycle

- Across a normal shock
- both total temperature and total pressure decrease
- both total temperature and total pressure remain constant
- total pressure remains constant but total temperature decreases
- total temperature remains constant but total pressure decreases

Answer:- total temperature remains constant but total pressure decreases

For calorifically perfect gas, across a normal shock- Mach number is subsonic
- Static pressure increases
- Total pressure decreases
- Static temperature increases
- Total temperature is constant
- Density increases
- entropy increases

- The Joukowskii airfoil is studied in aerdynamics because
- it is used in many aircraft
- it is easily transformed into a circle, mathematically
- it has a simple geometry
- it has the highest lift curve slope among all aifoils

Answer:- it is easily transformed into a circle, mathematically

- One of the criteria for high-speed airplanes is that the critical Mach number should be as high as possible. Therefore, high-speed subsonic airplanes are usually designed with
- thick airfoils
- thin airfoils
- laminar flow airfoils
- dimond airfoils

Answer:- thin airfoil

# GATE 2007 AEROSPACE ENGINEERING (Q 11-20)

Advertisements