Aerospace Engineering Gate 2013 Questions with Answer

Ques 14 GATE 2013

The mass flow rate of air through an aircraft engine is 10 kg/s. The compressor outlet temperature is 400 K and the turbine inlet temperature is 1800 K. The heating value of the fuel is 42 MJ/kg and the specific heat at constant pressure is 1 kJ/kg-K The mass flow rate of the fuel in kg/s is approximately

Ques 15 GATE 2013

For a given inlet condition, if the turbine inlet temperature is fixed, what value of compressor efficiency given below leads to the lowest amount of fuel added in the combustor of a gas turbine engine?

Ques 16 GATE 2013

A gas turbine engine is mounted on an aircraft which can attain a maximum altitude of 11 km from sea level. The combustor volume of this engine is decided based on conditions at

Ques 17 GATE 2013

Which one of the following shows the CORRECT variation of stagnation temperature along the axis of an ideal ram jet engine?

Ques 18 GATE 2013

A rocket motor has a chamber pressure of 100 bar and chamber temperature of 3000 K. The ambient pressure is 1 bar. Assume that the specific heat at constant pressure is 1 kJ/kg-K Also assume that the flow in the nozzle is isentropic and optimally expanded. The exit static temperature in K is

Ques 19 GATE 2013

Thrust of liquid oxygen - liquid hydrogen rocket engine is 300 kN. The O/F ratio used is 5. If the fuel mass flow rate is 12.5 kg/s, the specific impulse of the rocket motor in Ns/kg is

Ques 20 GATE 2013

In a 50% reaction axial compressor stage, the local blade velocity is 300 m/s and the axial component of velocity is 100 m/s If the absolute inlet flow angle α₁=45° the work per unit mass done on the fluid by the stage in kJ/kg is

Ques 21 GATE 2013

Consider two rockets P and Q fired vertically up with identical specific impulse and a payload of 2 kg. Rocket P has 2 identical stages, and each stage has 200 kg of propellant and 20 kg of structural weight. Rocket Q has a single stage with 400 kg of propellant and 40 kg of structural weight. Neglecting drag and gravity effects, the ratio of the change in velocity of P to that attained by Q is

Ques 22 GATE 2013

An aircraft is flying at Mach number M = 1.5, where the ambient temperature is 250 K. The stagnation temperature of gases at the entry to the nozzle is 800 K. The nozzle is choked and always under expanded. Assume the molecular weight of the exhaust gases to be 29, the ratio of specific heats to be 1.4 and the universal gas constant is 8314 J/kmol-K.
For which one of the nozzle exit Mach numbers given below is the propulsive efficiency highest?

Ques 23 GATE 2013

An aircraft is flying at Mach number M = 1.5, where the ambient temperature is 250 K. The stagnation temperature of gases at the entry to the nozzle is 800 K. The nozzle is choked and always under expanded. Assume the molecular weight of the exhaust gases to be 29, the ratio of specific heats to be 1.4 and the universal gas constant is 8314 J/kmol-K.
For which one of the nozzle exit Mach numbers given below is the thrust highest?

Ques 24 GATE 2013

The cross-section of a long thin-walled member is as shown in the figure. When subjected to pure twist, point A

Ques 25 GATE 2013

The channel section of uniform thickness 2mm shown in the figure is subjected to a torque of 10 Nm. If it is made of a material with shear modulus of 25 GPa, the twist per unit length in radians/m is

Ques 26 GATE 2013

The stiffened cross-section of a long slender uniform structural member is idealized as shown in the figure below. The lumped areas at A, B, C and D have equal cross-sectional area of 3 cm². The webs AB, BC, CD and DA are each 5 mm thick. The structural member is subjected to a twisting moment of 10 kNm. The magnitudes of the shear flow in the webs, q_AB, q_BC, q_CD, and q_DA in kN/m are, respectively