← MES Jr. Grade
Past Questions
A discrete time system is stable if all the roots of the characteristics equation lie :
A)
Outside the circle of unit radius
B)
Within the circle of unit radius
C)
Outside the circle of radius equal to 3-units
D)
On the circle of infinite radius.
In the analysis of discrete-time systems, stability is determined by the location of the poles of the system's transfer function (which are the roots of the characteristic equation) in the z-plane.
1. **The z-Transform and Stability**: For a causal discrete-time system to be Bounded-Input Bounded-Output (BIBO) stable, the region of convergence (ROC) of the transfer function must include the unit circle (|z| = 1).
2. **Pole Location**: For a causal system, the ROC is the exterior of a circle centered at the origin with a radius equal to the magnitude of the outermost pole. Therefore, for the ROC to include the unit circle, all poles (roots of the characteristic equation) must lie strictly inside the unit circle (|z| < 1).
3. **Analysis of Options**:
- **Option (a)**: If poles are outside the unit circle, the system is unstable because the impulse response will grow exponentially.
- **Option (b)**: This is the correct condition. All roots must be within the unit circle (|z| < 1) for stability.
- **Option (c)**: A radius of 3 units is arbitrary and does not define the stability boundary for general discrete systems.
- **Option (d)**: A circle of infinite radius is not a valid boundary for stability analysis.
State and prove the final value theorem with regard to Z transform.
With neat circuit diagram explain the operation of SCR as a half wave rectifier and full wave rectifier.
What does BOD stand for with reference to waste water?
A)
basis of distribution
B)
biodegradable oxygen demand
C)
biochemical oxygen demand
D)
basis of design
BOD stands for Biochemical Oxygen Demand. It is the amount of dissolved oxygen required by aerobic microorganisms to decompose organic matter in wastewater. The other options are incorrect because BOD is not related to basis of distribution, biodegradable oxygen demand, or basis of design.
With respect to energy conservation and cost efficiency, the nature of an ideal built form should be
A)
High Rise Low Density
B)
Medium Rise High Density
C)
Low Rise High Density
D)
Low Rise Low Density
For energy conservation and cost efficiency, an ideal built form should minimize exposed surface area while accommodating more users within a compact area. Low-rise high-density development reduces infrastructure, circulation, and construction costs compared to high-rise forms, while also improving energy efficiency through better compactness. High-rise low-density is the least efficient, and low-rise low-density uses too much land and services. Hence, the correct choice is Low Rise High Density.
What is the time period for which the water is stored in fill and draw type of sedimentation tank?
A)
24 hours
B)
48 hours
C)
52 hours
D)
76 hours
In a fill-and-draw sedimentation tank, the tank is filled, water is allowed to remain quiescent for settling, and then the clarified water is drawn off. The usual storage/settling period is about 48 hours. Hence, option (b) is correct. The other options do not match the standard detention period for this type of tank.
As per IS: 1172–1963, water required per head per day for average domestic purposes is
A)
65 litres
B)
85 litres
C)
105 litres
D)
135 litres
As per IS 1172:1963, the recommended water demand for average domestic purposes is 65 litres per head per day. This standard value is commonly used in water supply and plumbing questions. The other options are not the standard value asked here.
Different Air Conditioners are given Star rating based on their
A)
cooling capacity
B)
power consumption
C)
technology used
D)
energy efficiency ratio
Star ratings for air conditioners are assigned based on their energy efficiency, commonly represented by the Energy Efficiency Ratio (EER) or related efficiency metrics such as ISEER in modern standards. Higher star rating means better energy performance and lower electricity consumption for the same cooling output. Cooling capacity alone does not determine star rating, and technology used is not the direct rating basis.
What is the first step of Environmental Impact Assessment?
A)
Project Monitoring
B)
Project Appraisal
C)
Project Implementation
D)
Project Identification and Proposal
Environmental Impact Assessment (EIA) begins at the earliest planning stage. The first step is identifying the project and preparing the proposal, because the likely environmental effects can only be assessed after the project is defined. Project appraisal, implementation, and monitoring come later in the process. Therefore, option (d) is correct.
Up to which point on the stress-strain curve is Hooke’s law valid?
A)
Elastic limit
B)
Yield point
C)
Proportionality limit
D)
Fracture point
Hooke’s law states that stress is directly proportional to strain, but only in the linear region of the stress-strain curve. This relation remains valid up to the proportionality limit. Beyond this point, stress is no longer exactly proportional to strain, although the material may still behave elastically up to the elastic limit. Therefore, the correct answer is proportionality limit. Elastic limit is a broader concept, yield point marks the start of plastic deformation, and fracture point is the failure point.
What is a solar chimney?
A)
a type of solar heating and cooling system
B)
a cooking stove that uses solar energy
C)
a solar water heater
D)
none of these
A solar chimney is a passive solar device that uses solar energy to create airflow for ventilation, heating, and cooling. It works by heating air in a vertical shaft, causing the warm air to rise and exit, which draws cooler air in. So it is best described as a solar heating and cooling system. The other options are incorrect because it is not a cooking stove and not specifically a water heater.
The property by which a body returns to its original shape after removal of force is called
A)
Ductility
B)
Elasticity
C)
Malleability
D)
Plasticity
Elasticity is the property of a material by which it returns to its original shape and size after the deforming force is removed. Ductility is the ability to be drawn into wires, malleability is the ability to be hammered into sheets, and plasticity means permanent deformation remains after removing the force.
What is the unit for stress?
A)
N/m2
B)
Nm2
C)
N/m
D)
Nm
Stress is defined as force per unit area. Therefore its SI unit is newton per square metre (N/m2), which is also called pascal (Pa). Option (b) Nm2 is force multiplied by area, and options (c) N/m and (d) Nm are not units of stress.
In an Environment Impact Assessment, what does EIS stand for?
A)
Environmental Impact Summary
B)
Environmental Intensity Summary
C)
Environmental Impact Statement
D)
Environmental Intensity Statement
In Environmental Impact Assessment (EIA), EIS stands for Environmental Impact Statement. It is the document that describes the likely environmental effects of a proposed project and the measures to mitigate adverse impacts. The other options are incorrect because 'Summary' and 'Intensity' are not the standard meanings of EIS in this context.
In an Architectural Competition, how many Architects should be there as Assessors?
A)
Less than half comparing to promoter’s organization
B)
At least half comparing to promoter’s organization
C)
Majority of at least by one comparing to promoter’s organization
D)
Majority of at least by two comparing to promoter’s organization
In an architectural competition, the jury/assessors should include architects in a proportion of at least half of the promoter’s organization to ensure professional fairness and design expertise. Hence, option (b) is correct. Options (a), (c), and (d) do not match the standard requirement stated for such competitions.
If the ph of water is 10, it indicates that the sample is
A)
acidic
B)
alkaline
C)
neutral
D)
none of these
pH 7 is neutral. Values below 7 are acidic, and values above 7 are alkaline/basic. Since the pH of the water is 10, it is alkaline. Therefore, option (b) is correct.
In a multi-storied building, the type of plumbing system suitable for reusing the sullage for non-potable use is
A)
Single stack system
B)
Partially ventilated single stack system
C)
One pipe system
D)
Two pipe system
In a multi-storied building, if sullage (waste water) is to be reused for non-potable purposes, the plumbing arrangement should keep the waste water separate from soil discharge. A two pipe system provides separate pipes: one for soil waste and another for sullage/waste water, making collection and reuse of sullage possible. Single stack, partially ventilated single stack, and one pipe systems are primarily designed for drainage convenience and hygiene, not for separating sullage for reuse.
What is the curing period of concrete work under normal weather conditions when using Ordinary Portland Cement?
A)
20 days
B)
12 days
C)
14 days
D)
25 days
For concrete work using Ordinary Portland Cement under normal weather conditions, the standard curing period is 14 days. This allows sufficient hydration of cement for proper strength development. The other options are not the usual standard period for OPC concrete curing under normal conditions.
Right to acquire light and air from the neighbor’s land is an example of
A)
Easement by express grant
B)
Easement by implied grant
C)
Easement by custom
D)
Easement by prescription
Under the Indian Easements Act, a right to receive light and air through a neighbor’s land is typically acquired by continuous, open, and uninterrupted enjoyment for the statutory period. That is an easement by prescription. It is not an express grant (created by agreement), not an implied grant (arising from circumstances of transfer), and not by custom (based on local usage).
As per IS 2502-1963, the hook allowance for stirrups of RCC columns and beams should not be less than
A)
50mm
B)
75 mm
C)
100mm
D)
25 mm
As per IS 2502:1963 (bending and fixing of bars for concrete reinforcement), the hook allowance for stirrups in RCC columns and beams should not be less than 50 mm. This is the standard minimum hook extension provided for proper anchorage. Hence, option (a) is correct. The other values are not the prescribed minimum allowance for stirrups.
Intercepting trap has a water seal of?
A)
200 mm
B)
150 mm
C)
100 mm
D)
75 mm
An intercepting trap is used in drainage systems to prevent foul gases from the public sewer from entering the house drain. It is designed with a deep water seal, typically 200 mm, to ensure effective blockage of sewer gases. By comparison, common traps like P-traps or S-traps generally have smaller water seals such as 75 mm or 50 mm. Hence, the correct answer is 200 mm.
What is a box union in plumbing?
A)
A device for joining together two threaded pipes
B)
A spigot and socket joint
C)
A pipe fitting with inside threads only
D)
A fitting for providing a sharp change of direction
A box union is a type of pipe union used to connect two threaded pipes so that they can be easily assembled and dismantled. It provides a detachable joint. Option (b) describes a spigot and socket joint, option (c) is a socket, and option (d) refers to an elbow or bend used for change of direction.
A steel truss with parallel upper and lower chords and inclined connecting members forming a series of equilateral triangles is known as
A)
Bowstring Truss
B)
Warren Truss
C)
Kingpost Truss
D)
Scissors Truss
A truss having parallel upper and lower chords with inclined members forming a series of equilateral triangles is a Warren truss. Its defining feature is the alternating triangular web system, which efficiently carries loads. Bowstring truss has a curved top chord, kingpost truss is a simple triangular roof truss with one central vertical member, and scissors truss has crossed/angled lower chords for vaulted roof forms.
A Demolition Contract for a building is awarded to the
A)
Lowest bidder
B)
Highest bidder
C)
Second lowest bidder
D)
Second highest bidder
In a demolition contract, the contractor gets value from the salvaged materials (bricks, steel, wood, fixtures, etc.). So the party willing to pay the most to take over the building is selected. Therefore, a demolition contract is awarded to the highest bidder. The other options are generally used in ordinary works contracts where the client pays the contractor, but here the contractor may pay for the right to demolish.
What is the SI unit of Bending moment?
A)
kN
B)
kN2
C)
kNm
D)
km
Bending moment is the product of force and perpendicular distance, so its SI unit is Newton-metre (N·m). In structural engineering, it is commonly expressed as kN·m. Option (c) is correct.
(a) kN is only force, not moment.
(b) kN2 is not a valid unit.
(d) km is a unit of length, not moment.