ME GATE 2012 - Online Test
Q1. An incompressible fluid flows over a flat plate with zero pressure gradients. The boundary layer
thickness is 1 mm at a location where the Reynolds number is 1000. If the velocity of the fluid
alone is increased by a factor of 4, then the boundary layer thickness at the same location, in mm
will be
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. Choose the most appropriate alternative from the options given below to complete the following
sentence.
Suresh’s dog is the one __________ was hurt in the stampede.
Answer : Option A
Explaination / Solution:
The correct answer is ‘that’. In the given sentence ‘was hurt in the stampede’ determines which
dog belongs to Suresh.
Q3. A thin walled spherical shell is subjected to an internal pressure. If the radius of the shell is
increased by 1% and the thickness is reduced by 1%, with the internal pressure remaining the
same, the percentage change in the circumferential (hoop) stress is
Answer : Option D
Explaination / Solution:
Q4. A solid steel cube constrained on all six faces is heated so that the temperature rises uniformly by
∆T. If the thermal coefficient of the material is α. Young’s modulus is E and the Poissons’s ratio
is υ, the thermal stress developed in the cube due to heating is
Answer : Option A
Explaination / Solution:
No Explaination.
Q5. A solid disc of radius r rolls without slipping on a horizontal floor with angular velocity ω and
angular acceleration α. The magnitude of the acceleration of the point of contact on the disc is
Answer : Option D
Explaination / Solution:
Tangential acceleration will be zero, radial acceleration will exist.
Hence, Total acceleration = rω2
Q6. Water (Cp = 4.18 kJ/kg.K) at 80℃ enters a counter flow heat exchanger with a mass flow rate of
0.5 kg/s. Air (Cp = 1 kJ/kg.K) enters at 30℃ with a mass flow rate of 2.09 kg/s. If the
effectiveness of the heat exchanger is 0.8, the LMTD (in ℃) is
Answer : Option C
Explaination / Solution:
Q7. The following are the data for two crossed helical gears used for speed reduction:
Gear I : Pitch circle diameter in the plane of rotation 80 mm and helix angle 30°
Gear II : Pitch circle diameter in the plane of rotation 120 mm and helix angle 22.5°
If the input speed is 1440 rpm, the output speed in rpm is
Answer : Option C
Explaination / Solution:
For helical gears
Q8. A large tank with a nozzle attached contains three immiscible, inviscid fluids as shown.
Assuming that the changes is h1, h2 and h3 are negligible, the instantaneous discharge velocity is
Answer : Option A
Explaination / Solution:
No Explaination.
Q9. For an opaque surface, the absorptivity (α), transmissivity (τ) and reflectivity (ρ) are related by
the equation:
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. A refrigerator operates between 120 kPa and 800 kPa in an ideal vapor compression cycle with R134a
as the refrigerant. The refrigerant enters the compressor as saturated vapor and leaves the condenser as saturated liquid. The mass flow rate of the refrigerant is 0.2 kg/s. Properties for R-134a
are as follows: 
The rate at which heat is extracted, in kJ/s from the refrigerated space is
Answer : Option A
Explaination / Solution:
No Explaination.
