Hello, here I am providing you the paper of GATE hold by IIT Mumbai and its answer key as under:

Which one of the following flight instruments is used on an aircraft to determine its attitude in
flight?
(A) Vertical speed indicator
(B) Altimeter
(C) Artificial Horizon
(D) Turn-bank indicator

A supersonic airplane is expected to fly at both subsonic and supersonic speeds during its whole
flight course. Which one of the following statements is TRUE?
(A) Airplane will experience less stability in pitch at supersonic speeds than at subsonic speeds
(B) Airplane will feel no change in pitch stability
(C) Airplane will experience more stability in pitch at supersonic speeds than at subsonic speeds
(D) Pitch stability cannot be inferred from the information given

Which one of the following is favorable for an airplane operation?
(A) Tail wind in cruise and head wind in landing
(B) Tail wind both in cruise and landing
(C) Head wind both in cruise and landing
(D) Head wind in cruise and tail wind in landing

Which one of the following is TRUE with respect to Phugoid mode of an aircraft?
(A) Frequency is directly proportional to flight speed
(B) Frequency is inversely proportional to flight speed
(C) Frequency is directly proportional to the square root of flight speed
(D) Frequency is inversely proportional to the square root of flight speed

Which one of the following statements is NOT TRUE for a supersonic flow?
(A) Over a gradual expansion, entropy remains constant
(B) Over a sharp expansion corner, entropy can increase
(C) Over a gradual compression, entropy can remain constant
(D) Over a sharp compression corner, entropy increases

The critical Mach number for a flat plate of zero thickness, at zero angle of attack, is _________

A damped single degree-of-freedom system is vibrating under a harmonic excitation with an
amplitude ratio of 2.5 at resonance. The damping ratio of the system is ______________

The cross-section of a long thin-walled member is as shown in the figure. When subjected to pure
twist, point A
(A) does not move horizontally or axially, but moves vertically
(B) does not move axially, but moves both vertically and horizontally
(C) does not move horizontally, vertically or axially
(D) does not move vertically or axially, but moves horizontally

Consider two engines P and Q. In P, the high pressure turbine blades are cooled with a bleed of 5%
from the compressor after the compression process and in Q the turbine blades are not cooled.
Comparing engine P with engine Q, which one of the following is NOT TRUE?
(A) Turbine inlet temperature is higher for engine P
(B) Specific thrust is higher for engine P
(C) Compressor work is the same for both P and Q
(D) Fuel flow rate is lower for engine P

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 ___________

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?
(A) 1 (B) 0.95 (C) 0.85 (D) 0.8
A
B C
D
200mm
500mm

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
(A) sea level (B) 8 km altitude (C) 5.5 km altitude (D) 11 km altitude
Q.23 Consider the low earth orbit (LEO) and the geo synchronous orbit (GSO). Then
(A) V requirement for launch to LEO is greater than that for GSO, and altitude of LEO is
lower than that of GSO
(B) V requirement for launch to LEO is lower than that for GSO, and altitude of LEO is
lower than that of GSO
(C) V requirement for launch to LEO is greater than that for GSO, and altitude of LEO is
greater than that of GSO
(D) V requirement for launch to LEO is lower than that for GSO, and altitude of LEO is
greater than that of GSO