Aerospace Engineering Gate 2010 Questions with Answer

Ques 40 GATE 2010

Given digits 2, 2, 3, 3, 3, 4, 4, 4, 4 how many distinct 4 digit numbers greater than 3000 can be formed?

Ques 41 GATE 2010

Hari (H), Gita (G), Irfan (1) and Saira (S) are siblings (i.e. brothers and sisters). All were born on
1" January. The age difference between any two successive siblings (that is born one after another)
is less than 3 years. Given the following facts:
i.Hari's age+Gita's age>Irtan's age+Saira's age.
ii. The age difference between Gita and Saira is 1 year. However, Gita is not the
oldest and Saira is not the youngest.
iii. There are no twins.
In what order were they born (oldest first)?

Ques 42 GATE 2010

For a multi-stage axial compressor with constant diameter hub

Ques 43 GATE 2010

How does the specific thrust, at constant turbine inlet temperature, produced by a turbofan engine
change with an increase in compressor pressure ratio?

Ques 44 GATE 2010

The maximum operating flow rate through a centrifugal compressor at a given RPM is limited by

Ques 45 GATE 2010

A missile with a Ramjet engine is flying in air. The temperature at the inlet and the outlet of the
combustor are 1200 K and 2500 K respectively. The heating value of the fuel is 43 MI/kg and the
burmer efficiency is 90%. Considering the working fluid to be air (C_r=1005 1/kgK and γ=1.4) the
fuel/air ratio (f=^m_s/_mα) for this engine is equal to:

Ques 46 GATE 2010

The inlet stagnation temperature for a single stage axial compressor is 300 K and the stage
efficiency is 0.80. Following conditions exist at the mean radius of the rotor blade:
Blade speed =200 m/s
Axial flow velocity =160 m/s
Inlet blade angle β₁=44^o
Outlet blade angle β₂=14^o
C_p=1005 I/kgK and γ=1.4
What is the stagnation pressure ratio (<P_RS>) for this compressor?

Ques 47 GATE 2010

An aircraft with an IDEAL Turbojet engine is flying at 200 m/s at an altitude where the ambient pressure is equal to 0.8 bar. The stagnation pressure and temperature at the inlet of the turbine are 6 bar and 1400 K respectively. The change in specific enthalpy across the compressor is 335 kJ/kg. Assume the fuel flow rate to be very small in comparison to the air flow rate and consider C_p = 1117 J/kg·K and γ = 1.3.
What is the stagnation pressure at the inlet of the nozzle?

Ques 48 GATE 2010

An aircraft with an IDEAL Turbojet engine is flying at 200 m/s at an altitude where the ambient pressure is equal to 0.8 bar. The stagnation pressure and temperature at the inlet of the turbine are 6 bar and 1400 K respectively. The change in specific enthalpy across the compressor is 335 kJ/kg. Assume the fuel flow rate to be very small in comparison to the air flow rate and consider C_p = 1117 J/kg·K and γ = 1.3.
What is the specific thrust produced by this engine under the given conditions?

Ques 49 GATE 2010

The angular momentum, about the centre of mass of the earth, of an artificial satellite in a highly
elliptical orbit is:

Ques 50 GATE 2010

Among the choices given below, the Specific Impulse is maximum for a

Ques 51 GATE 2010

The stagnation pressure and stagnation temperature inside the combustion chamber of a liquid
rocket engine are 1.5 MPa and 2500 K respectively. The burned gases have γ=1.2 and
R=692.83 J/kgK. The rocket has a converging - diverging nozzle with a throat area of 0.025 m²
and the flow at the exit of the nozzle is supersonic. If the flow through the nozzle is isentropic, what
is the mass flow rate of the gases out of the nozzle?

Ques 52 GATE 2010

A two stage chemical rocket, having the same specific impulse (l_9p) of 300 s for both the stages is
designed in such a way that the payload ratio and the structural ratio are same for both the stages.
The second stage of the rocket has following mass distribution:
Propellant Mass=10208 kg
Structural Mass=1134 kg
Payload Mass=1700 kg
g_c=9.8 m/s²
If the rocket is fired from rest and it lies in a zero gravity field and a drag free environment, the
final velocity attained by the payload is