MES Jr. Grade • Paper-II
Effect of friction, at the sleeve of a centrifugal governor is to make it
A)
More sensitive
B)
More stable
C)
Insensitive over a small range of speed
D)
Unstable
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'More stable' (Option B).
MES Jr. Grade • Paper-II
Which of the following plane mechanism represents the structure
A)
Three-bar mechanism
B)
Four-bar mechanism
C)
Five-bar mechanism
D)
Six-bar mechanism
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'Six-bar mechanism' (Option D).
MES Jr. Grade • Paper-II
In a kinematic chain, a quaternary joint is equivalent to
A)
One binary joint
B)
Two binary joint
C)
Three binary joint
D)
Four binary joint
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'Two binary joint' (Option B).
MES Jr. Grade • Paper-II
Limit of proportionality depends upon
A)
area of cross- section
B)
type of loading
C)
type of material
D)
all of the above
Based on established principles in Mechanical Engineering, the correct and most appropriate choice is 'all of the above' (Option D).
MES Jr. Grade • Paper-II
The working surface above the pitch surface of the gear tooth is termed as
A)
Addendum
B)
Dedendum
C)
Flank
D)
Face
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'Flank' (Option C).
MES Jr. Grade • Paper-II
Match list-I (application) with list-II (drive element) and select the correct answer using the codes given below the lists:
List-I: A. Automobile differential, B. Bicycle, C. Planning machine, D. Radiator fan of automobile
List-II: 1. Flat belt, 2. V- belt, 3. Chain drive, 4. Gear drive
A)
4 3 1 2
B)
1 3 4 2
C)
4 2 1 3
D)
1 2 4 3
Based on established principles in the relevant subject area, the correct and most appropriate choice is '4 3 1 2' (Option A).
MES Jr. Grade • Paper-II
Failure of a material is called fatigue when it fails
A)
At the elastic limit
B)
Below the elastic limit
C)
At the yield point
D)
Below the yield point
Based on established principles in Mechanical Engineering, the correct and most appropriate choice is 'Below the elastic limit' (Option B).
MES Jr. Grade • Paper-II
In a slider-crank mechanism, the velocity of piston becomes maximum when
A)
Crank and connecting rod are in line with each other
B)
Crank is perpendicular to the line of stroke of the piston
C)
Crank and connecting rod are perpendicular
D)
Crank is 1200 with the line of stroke
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'Crank and connecting rod are in line with each other' (Option A).
MES Jr. Grade • Paper-II
The maximum bending moment caused by a moving load on a fixed- ended beam is
A)
at the support end
B)
under the load only
C)
always at the mid span
D)
none of the above
Based on established principles in Mechanical Engineering, the correct and most appropriate choice is 'at the support end' (Option A).
MES Jr. Grade • Paper-II
An orthotropic material has
A)
non- homogeneous properties
B)
inelastic properties
C)
different properties in three perpendicular directions
D)
same properties in orthogonal directions
Based on established principles in Mechanical Engineering, the correct and most appropriate choice is 'same properties in orthogonal directions' (Option D).
MES Jr. Grade • Paper-II
A higher pair can be replaced by a
A)
Two revolute pair and two additional linkages
B)
Two revolute pair and one additional linkages
C)
One revolute pair and one additional linkages
D)
None of these
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'One revolute pair and one additional linkages' (Option C).
MES Jr. Grade • Paper-II
The maximum deflection of a beam occurs at
A)
zero bending moment location
B)
zero shear force location
C)
zero slope location
D)
none of these
Based on established principles in Mechanical Engineering, the correct and most appropriate choice is 'zero slope location' (Option C).
MES Jr. Grade • Paper-II
In the case of a flywheel, the maximum fluctuation of energy is the
A)
Sum of maximum and minimum energies
B)
Difference between the maximum and minimum energies
C)
Ratio of the maximum and minimum energy
D)
Ratio of the minimum and maximum energy
Based on established principles in the relevant subject area, the correct and most appropriate choice is 'Ratio of the minimum and maximum energy' (Option D).
MES Jr. Grade • Paper-II
Buckling load of a column depends upon:
i. length of the column
ii. least lateral dimension
iii. cross-sectional area of the column
A)
only (i)
B)
only (iii)
C)
both (i) and (ii)
D)
(i), (ii) and (iii)
Based on established principles in Mechanical Engineering, the correct and most appropriate choice is '(i), (ii) and (iii)' (Option D).
MES Jr. Grade • Paper-I
The total energy developed by the hydraulic oil in a system is given as
A)
Total energy = (Potential energy + Pressure energy)
B)
Total energy = (Potential energy + Kinetic energy)
C)
Total energy = (Potential energy – Kinetic energy)
D)
none of these
Option D: none of these. This matches the standard definition or established fact for the concept asked.
MES Jr. Grade • Paper-I
A counter flow shell and tube heat exchanger is used to heat water with hot exhaust gases. The water (c=4180 J/kgK) flows at the rate of 2 kg/s and the exhaust gases (c=1000 J/kgK) flow at the rate of 5 kg/s. If the heat transfer surface area is 32 m2 and the overall heat transfer coefficient is 200 W/m2K. The NTU of the heat exchanger is
A)
4.5
B)
2.4
C)
8.6
D)
1.28
NTU=UA/Cmin=(200×32)/(5×1000)=1.28.
MES Jr. Grade • Paper-I
The temperature range for transition boiling is:
A)
30°C ≤ ΔT ≤ 150°C
B)
5°C ≤ ΔT ≤ 30°C
C)
30 ≤ ΔT ≤ 120°C
D)
ΔT ≥ 150°C
Transition boiling occurs between nucleate and film boiling, roughly over the stated intermediate temperature-difference range.
MES Jr. Grade • Paper-I
In MLTu system, the dimension of thermal conductivity is
A)
ML-1T-1θ-1
B)
MLT-1θ-1
C)
MLT-3θ-1
D)
MLT-2θ-1
Thermal conductivity has dimensions of power/(length×temperature) = MLT⁻³Θ⁻¹.
MES Jr. Grade • Paper-I
For a fully developed laminar flow through a pipe with uniform wall temperature, the heat transfer coefficient is
A)
not directly proportional to the thermal conductivity of fluid film
B)
inversely proportional to the pipe diameter
C)
dependent on fluid velocity
D)
dependent on fluid viscosity
Option C: dependent on fluid velocity. The result follows from the standard engineering relationship for the stated conditions.
MES Jr. Grade • Paper-I
A wall of thickness 0.6 m has width and has a normal area 1.5 m2 and is made up of material of thermal conductivity 0.4 W/mK. The temperatures on the two sides are 800°C. What is the thermal resistance of the wall?
A)
2 K/W
B)
3.5 K/W
C)
1 K/W
D)
2.3 K/W
Thermal resistance R=L/(kA)=0.6/(0.4×1.5)=1 K/W.
MES Jr. Grade • Paper-I
Heat transfer takes place as per -
A)
zeroth law of thermodynamics
B)
first law of thermodynamic
C)
second law of the thermodynamics
D)
Kirchoff’s law
Option C: second law of the thermodynamics. The result follows from the standard engineering relationship for the stated conditions.
MES Jr. Grade • Paper-I
Upto the critical radius of insulation
A)
Added insulation will increase heat loss
B)
Added insulation will decrease heat loss
C)
Convective heat loss will be less than conductive heat loss
D)
Heat flux will decrease
Below the critical radius of insulation, adding insulation can initially increase heat loss because the surface-area effect outweighs the added conduction resistance.
MES Jr. Grade • Paper-I
When is a pressure reducing valve used?
A)
it is used when higher pressure than system pressure is required
B)
it is used when lower pressure than system pressure is required
C)
when absolute zero pressure is required
D)
all of these
Option B: it is used when lower pressure than system pressure is required. This matches the standard definition or established fact for the concept asked.
MES Jr. Grade • Paper-I
A plane wall is 25 cm thick with an area of 1 m2, and has a thermal conductivity of 0.5 W/mK. If a temperature difference of 60°C is imposed across it, what is the heat flow?
A)
180 W
B)
140 W
C)
120 W
D)
160 W
Q=kAΔT/L=0.5×1×60/0.25=120 W.
MES Jr. Grade • Paper-I
A composite wall has two layers of different materials having thermal conductivities of k1 and k2. If each layer has the same thickness, the equivalent thermal conductivity of the wall is
A)
(k1 + k2) / (k1 + k2)
B)
k1 k2 / (k1 + k2)
C)
2k1 k2 / (k1 + k2)
D)
(k1 + k2) / 2
For equal thickness layers in series, keq=2k1k2/(k1+k2).
