Aerospace Engineering Gate 2014 Questions with Answer

Ques 14 GATE 2014

For a given fuel flow rate and thermal efficiency, the take-off thrust for a gas turbine engine burning aviation turbine fuel (considering fuel-air ratiof<<1) is

Ques 15 GATE 2014

For a fifty percent reaction axial compressor stage, following statements are given:
I. Velocity triangles at the entry and exit of the rotor are symmetrical
II. The whirl or swirl component of absolute velocity at the entry of rotor and entry of stator are same. Which of the following options are correct?

Ques 16 GATE 2014

A small rocket having a specific impulse of 200s produces a total thrust of 98kN, out of which 10kN is the pressure thrust. Considering the acceleration due to gravity to be 9.8m/s², the propellant mass flow rate in kg/s is

Ques 17 GATE 2014

The thrust produced by a turbojet engine

Ques 18 GATE 2014

A cruise missile with an ideal ramjet engine is flying at Mach 4.0 at an altitude where the ambient temperature is 100K. Considerratio of specific heatsy =1.4 and specific gas constant R=287J/kgK If the stagnation temperature in the combustion chamber is equal to 2310K, the speed of the exhaust gases (in m/s) is

Ques 19 GATE 2014

A gas turbine engine is operating under the following conditions:

Stagnation temperature at turbine inlet 1350 K
Stagnation pressure at the turbine inlet 10 bar
Static temperature at turbine exit 800 K
Velocity at turbine exit 200 m/s
Total-to-total efficiency of turbine 0.96
y (ratio of specific heats) 1.33
Cp(specific heat at constant pressure) 1.147 kJ/kgK

The stagnation pressure (in bar) in the nozzle (considering isentropic nozzle) is equal to

Ques 20 GATE 2014

Air at a stagnation temperature of 300K (ratio of specific heats, γ=1.4 and specific gas constant R =287 J/kgK) enters the impeller of a centrifugal compressor in axial direction. The stagnation pressure ratio between the diffuser outlet and impeller inlet is 4.0. The impeller blade radius is 0.3 m and it is rotating at 15000 rev/min. If the slip factor σ_s (Ratio of tangential component of air velocity at the blade tip to the blade tip speed) is 0.88, the overall efficiency (total-to-total) of the compressor (in %) is

Ques 21 GATE 2014

A stationary two stage rocket with initial mass of 16000kg, carrying a payload of 1000kg, is fired in a vertical trajectory from the surface of the earth. Both the stages of the rocket have same specific impulse, I_sp, of 300s and same structural coefficient of 0.14. The acceleration due to gravity is 9.8m/s² Neglecting drag and gravity effects and considering both the stages with same payload ratio, the terminal velocity attained by the payload in m/s is

Ques 22 GATE 2014

A cryogenic rocket has a specific impulse of 455s and characteristic velocity of 2386 m/s. The value of thrust coefficient for this rocket is

Ques 23 GATE 2014

It is desired to measure the Young's modulus and the Poisson's ratio of a given homogeneous, isotropic material. A bar of length 20cm and square cross-section (10mm×10mm) of this material is subjected to a tensile load of 40kN. Under this load, length increases to 20.1cm while the cross-section reduces to 9.98mm×9.98mm Young's modulus and Poisson's ratio of the material are:

Ques 24 GATE 2014

In general, for any given solid subjected to arbitrary loading, which of the following statements is always true:

Ques 25 GATE 2014

Which one of the following objects with inclined face at 45°, subjected to the given stresses, are in static equilibrium:

Ques 26 GATE 2014

The boundary conditions for a rod with circular cross-section, under torsional vibration, are changed from fixed-free to fixed-fixed. The fundamental natural frequency of the fixed-fixed rod is k times that of fixed-free rod. The value of k is