← MES Jr. Grade
Past Questions
Margin of safety is generally expressed as
A)
ratio of budgeted sales to sales at BEP
B)
ratio of actual sales to sales at BEP
C)
percentage of budget to BEP
D)
all of these
Margin of safety is the excess of actual sales over break-even sales. It is commonly expressed as a ratio or percentage of actual sales, but among the given options the correct expression is the ratio of actual sales to sales at BEP. Option (a) is not the standard definition, option (c) is incorrect, and option (d) is wrong because not all statements are correct.
The property of the material due to which it can cut another material is known as
A)
ductility
B)
malleability
C)
hardness
D)
none of these
The ability of a material to cut or resist being cut by another material is called hardness. Ductility is the ability to be drawn into wires, and malleability is the ability to be hammered into thin sheets. Therefore, the correct answer is hardness.
Delta iron occurs at temperature of
A)
room temperature
B)
above melting point
C)
between 14000C and 15390C
D)
between 9100C and 14000C
Delta iron (δ-iron) is the high-temperature allotrope of iron. It exists from about 1394°C up to the melting point of iron at 1538–1539°C. Therefore, the correct option is (c) between 1400°C and 1539°C. Options (a) and (d) correspond to room temperature and the γ-iron range respectively, while (b) is incorrect because delta iron exists below the melting point, not above it.
Hot-chamber die-casting process is used for
A)
Aluminium
B)
Zinc
C)
Cast iron
D)
Steel
Hot-chamber die-casting is used for low-melting-point, non-ferrous metals that do not attack the machine components. Zinc is the standard material for hot-chamber die casting. Aluminium is generally cast by the cold-chamber process because its higher melting temperature would damage the submerged injection system. Cast iron and steel have much higher melting points and are not suitable for die casting.
The angle obtained between the machined surface and underside of the tool is generally named as
A)
clearance angle
B)
relief angle
C)
edge angle
D)
nose angle
The angle between the machined surface and the underside of the cutting tool is called the relief angle. It provides clearance so the tool does not rub against the workpiece. Clearance angle is a related term often used similarly, but in standard tool geometry terminology, the angle between the machined surface and the tool’s underside is the relief angle. Edge angle and nose angle refer to other parts of the cutting edge geometry, not this angle.
Work study is concerned with
A)
improving present method and finding standard time
B)
motivation of workers
C)
improving production capability
D)
all of these
Work study in industrial engineering consists of method study and work measurement. Method study aims at improving the present method of doing a job, and work measurement is used to determine the standard time required for the job. It is not primarily concerned with motivation of workers or general production capability, so option (a) is correct.
In sand casting, draft allowance is added to
A)
All linear dimensions
B)
Only the interior dimensions
C)
Only the exterior dimensions
D)
Only to the dimensions that are perpendicular to the parting plane
Draft allowance is the taper provided on vertical faces of a pattern so that it can be withdrawn easily from the sand mold without damaging the cavity. Therefore, it is applied to surfaces/dimensions perpendicular to the parting plane, not to all dimensions. Interior or exterior dimensions are not the rule; the key criterion is the direction relative to the parting plane.
The relation between Young’s modulus (E), bulk modulus (G) and Poisson’s ratio (µ) of an elastic material is
A)
E = 3G (1 - 2µ)
B)
E = 2G (1 - 2µ)
C)
E = 2G (1 + µ)
D)
E = 2G (1 - µ)
For an isotropic elastic material, the standard relation between Young’s modulus (E), shear modulus (G), and Poisson’s ratio (µ) is E = 2G(1 + µ). The other common relation is E = 3K(1 - 2µ), where K is the bulk modulus. Since the question uses G in the options, the correct formula is option (c).
Self-locking is not possible in the case of
A)
simple band brake
B)
differential band brake
C)
simple block brake
D)
internal expanding shoe brake
Self-locking occurs when the frictional action of the brake is sufficient to keep it applied without external force. In a differential band brake, the two ends of the band are arranged so that the tensions act in opposite ways, and the brake can be designed to be self-energizing, but true self-locking is not possible in the same way as in a simple band brake. Simple band brakes, simple block brakes, and internal expanding shoe brakes can be arranged to be self-locking under suitable conditions. Therefore, the correct answer is differential band brake.
The ratio of the lateral strain to the linear strain is called
A)
modulus of rigidity
B)
Poisson’s ratio
C)
bulk modulus
D)
modulus of elasticity
Poisson’s ratio is defined as the ratio of lateral strain to longitudinal (linear) strain. Hence the correct answer is Poisson’s ratio. The other options are different elastic constants: modulus of rigidity relates shear stress to shear strain, bulk modulus relates volumetric stress to volumetric strain, and modulus of elasticity relates normal stress to normal strain.
The product of circular pitch and diameteral pitch is equal to
A)
module
B)
unity
C)
D)
1/
For gears, circular pitch (pc) = πm and diametral pitch (Pd) = 1/m, where m is the module. Therefore, pc × Pd = (πm) × (1/m) = π. Hence the correct answer is π. Option (a) module is incorrect because module is the reciprocal of diametral pitch, not the product. Option (b) unity is incorrect because the product is not 1. Option (d) 1/π is the reciprocal of the correct value.
Coriolis component of acceleration is considered in case of
A)
quick return motion mechanism
B)
slider crank mechanism
C)
four bar mechanism
D)
none of these
Coriolis component of acceleration arises when a slider moves relative to a rotating link. This is commonly encountered in mechanisms like the quick return motion mechanism (e.g., Whitworth quick return mechanism), where a sliding block moves in a rotating slotted link. It is not generally associated with a simple slider-crank mechanism or a four-bar mechanism in the usual exam context.
Oldhum coupling is used to connect
A)
aligned shafts
B)
shafts with lateral misalignment
C)
intersecting shafts
D)
parallel shafts
Oldham coupling is specifically used to connect two parallel shafts whose axes are slightly laterally displaced. It accommodates parallel misalignment by using a floating middle disc. Therefore, the correct answer is parallel shafts. It is not used for aligned shafts (no coupling correction needed), intersecting shafts, or general lateral misalignment between non-parallel shafts.
A shaft directly coupled to a power source is called
A)
line shaft
B)
counter shaft
C)
flexible shaft
D)
jack shaft
A shaft directly coupled to a power source is called a line shaft. It transmits power from the source to other machines. A counter shaft is an intermediate shaft used to transmit power from a line shaft to machines, a flexible shaft is used where alignment is difficult, and a jack shaft is a short auxiliary shaft used in power transmission systems.
Frequency of vibrations is usually expressed in
A)
Number of cycles per hour
B)
Number of cycles per second
C)
Number of cycles per minute
D)
Number of cycles per day
Frequency is defined as the number of complete vibrations or cycles occurring in one second. Its SI unit is hertz (Hz), which means cycles per second. Therefore, option (b) is correct. The other options use hour, minute, or day, which are not the standard expression for frequency.
A kinematic chain is called a mechanism, if the number of fixed links is
A)
at most one
B)
at least one
C)
more than one
D)
none of these
A kinematic chain becomes a mechanism when one of its links is fixed, so that the relative motion of the remaining links is constrained and useful motion is obtained. Therefore, the number of fixed links must be at least one. If no link is fixed, it remains only a kinematic chain, not a mechanism.
When two non-intersecting and non-coplanar shafts are connected by gears, the arrangements are known as
A)
spur gearing
B)
helical gearing
C)
bevel gearing
D)
spiral gearing
When two shafts are non-intersecting and non-coplanar, the gear arrangement used is called spiral gearing (also known as crossed helical gearing). Spur gears are for parallel shafts, bevel gears are for intersecting shafts, and helical gears are generally used for parallel shafts with smoother operation.
A beam is loaded as cantilever. If the load at the free end is increased, the failure will occur
A)
at the point of the load
B)
at the middle of the beam
C)
at the fixed end of the beam
D)
at any location of the beam
In a cantilever beam with a load at the free end, the bending moment is maximum at the fixed support and zero at the free end. Since failure in bending occurs where the bending stress is highest, the beam will fail at the fixed end. The other options are incorrect because the load point has no maximum moment, the middle is not the critical section, and failure does not occur at any arbitrary location.
In designing a plate clutch, assumption of uniform wear conditions is made because it leads to
A)
real life design
B)
safer design
C)
cost effective design
D)
efficient design
In plate clutch design, the uniform wear theory assumes that wear is proportional to pressure × radius and that the product p·r remains constant. This gives a more conservative estimate of torque capacity than the uniform pressure theory, so it is preferred for design. Hence, the assumption of uniform wear leads to a safer design. The other options are not the standard reason used in clutch design theory.
Rankine’s theory of failure is applicable for which of the following type of materials?
A)
brittle
B)
ductile
C)
elastic
D)
plastic
Rankine’s theory is the maximum principal stress theory. It states that failure occurs when the maximum principal stress reaches the ultimate stress in simple tension. This theory is mainly applicable to brittle materials such as cast iron, glass, and concrete, which fail suddenly with little plastic deformation. Ductile materials are better explained by theories like Tresca and von Mises.
The load required to produce unit deflection in a spring is called
A)
stiffness constant
B)
strain constant
C)
rigidity constant
D)
torsional constant
The load required to produce unit deflection in a spring is called the spring stiffness or stiffness constant. It is defined as load per unit deflection. The other options are not standard terms for this definition: strain constant is not used for springs, rigidity constant relates to material rigidity, and torsional constant relates to torsion of shafts.
The maximum bending moment in a simply supported beam carrying a total load W, uniformly distributed on the entire span L is equal to
A)
WL/2
B)
WL/3
C)
WL/4
D)
WL/8
For a simply supported beam with a uniformly distributed load W over the full span L, the reactions at the supports are W/2 each. The bending moment is maximum at midspan. The maximum bending moment is given by Mmax = wL^2/8, where w = W/L. Substituting gives Mmax = (W/L) × L^2 / 8 = WL/8. Hence, the correct answer is (d). The other options do not match the standard bending moment formula for a full-span UDL.
A round key is used for
A)
light duty
B)
medium duty
C)
heavy duty
D)
extra heavy duty
A round key is generally used for medium duty applications. It is suitable where moderate torque transmission is required. Light duty keys are usually saddle keys, while heavy and extra heavy duty applications typically use sunk keys or special keys designed for greater load transmission.
A shaft with collars at both ends fitted into a circular hole is a popular example of
A)
rolling pair
B)
turning pair
C)
sliding pair
D)
spherical pair
A shaft fitted into a circular hole can rotate about its axis relative to the hole. Since the relative motion is pure rotation, it forms a turning pair. A rolling pair involves rolling contact, a sliding pair involves only sliding motion, and a spherical pair allows angular motion in all directions about a point.
The bending moment diagram for a cantilever beam carrying uniformly distributed load will be a
A)
rectangle
B)
triangle
C)
parabola
D)
hyperbola
For a cantilever beam carrying a uniformly distributed load (UDL), the shear force varies linearly along the length of the beam. Since bending moment is the integral of shear force, the bending moment varies as a second-degree curve, i.e., a parabola. Hence, the bending moment diagram is parabolic. A rectangle would correspond to constant bending moment, a triangle to linearly varying bending moment, and a hyperbola is not the correct shape here.