ME GATE 2012 - Online Test
Q1. In a DC arc welding operation, the voltage-arc length characteristic was obtained as Varc = 20 + 5l where the arc length l was varied between 5 mm and 7 mm. Here Varc denotes the arc voltage
in Volts. The arc current was varied from 400 A to 500 A. Assuming linear power source
characteristic, the open circuit voltage and the short circuit current for the welding operation are
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. In a single pass rolling process using 410 mm diameter steel rollers, a strip of width 140 mm and
thickness 8 mm undergoes 10% reduction of thickness. The angle of bite in radians is
Answer : Option C
Explaination / Solution:
No Explaination.
Q3. Steam enters an adiabatic turbine operating at steady state with an enthalpy of 3251.0 kJ/kg and
leaves as a saturated mixture at 15 kPa with quality (dryness fraction) 0.9. The enthalpies of the
saturated liquid and vapor at 15 kPa are hf = 225.94 kJ/kg and hg = 2598.3 kJ/kg respectively.
The mass flow rate of steam is 10 kg/s. Kinetic and potential energy changes are negligible. The
power output of the turbine in MW is
Answer : Option C
Explaination / Solution:
Q4. Calculate the punch size in mm, for a circular blanking operation for which details are given
below.
Size of the blank 25 mm
Thickness of the sheet 2 mm
Radial clearance between punch and die 0.06 mm
Die allowance 0.05 mm
Answer : Option A
Explaination / Solution:
No Explaination.
Q5. Oil flows through a 200 mm diameter horizontal cast iron pipe (friction factor, f = 0.0225) of
length 500 m. The volumetric flow rate is 0.2 m3/s. The head loss (in m) due to friction is (assume g = 9.81 m/s2)
Answer : Option A
Explaination / Solution:
4f = 0.0225 
L = 500 m
Q = 0.2 m3/s
Q6. An ideal gas of mass m and temperature T1 undergoes a reversible isothermal process from an
initial pressure P1 to final pressure P2. The heat loss during the process is Q. The entropy change ∆S of the gas is
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. Which one of the following configurations has the highest fin effectiveness?
Answer : Option A
Explaination / Solution:
For a given configuration, Thin, closely spaced fins can achieve maximum heat transfer area.
Hence, more effective.
Q8. The velocity triangles at the inlet and exit of the rotor of a turbo-machine are shown. V denotes
the absolute velocity of the fluid, W denotes the relative velocity of the fluid and U denotes the
blade velocity. Subscripts 1 and 2 refer to inlet and outlet respectively. If V2 = W1 and V1 = W2,
then the degree of reaction is
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. A room contains 35 kg of dry air and 0.5 kg of water vapor. The total pressure and temperature of
air in the room are 100 kPa and 25℃ respectively. Given that the saturation pressure for water at
25℃ is 3.17 kPa, the relative humidity of the air in the room is
Answer : Option D
Explaination / Solution:
No Explaination.
Q10. Choose the most appropriate alternative from the options given below to complete the following
sentence:
Despite several _____________ the mission succeeded in its attempt to resolve the conflict.
Answer : Option B
Explaination / Solution:
The word despite tells us that mission succeeded even though there were problems. Hence the
correct answer is Setbacks
