← MES Jr. Grade
Past Questions — 2015
Which transformation distorts the geometry of object?
A)
shearing
B)
rotation
C)
scaling
D)
None of these
Shearing changes the shape of an object by slanting it, so its geometry gets distorted. Rotation only changes orientation, and scaling changes size but generally preserves shape proportions if uniform. Therefore, the transformation that distorts geometry is shearing.
__________ provides a larger size of virtual memory but requires virtual memory which provides multidimensional memory.
A)
Paging method
B)
Segmentation method
C)
Paging and segmentation method
D)
None of these
Segmentation divides a program into logical, variable-sized segments such as code, data, and stack. This gives the user a larger and more flexible virtual memory view, often described as multidimensional or logically organized memory. Paging mainly provides fixed-size blocks and does not naturally offer this logical structure. Paging and segmentation together can also be used, but the statement best matches segmentation method.
In which method is address of object implicitly passed to the called function?
A)
Pass-by-value
B)
Pass-by-reference
C)
Both (a) and (b)
D)
None of these
In pass-by-reference, the called function receives a reference/address to the original object, so changes made inside the function affect the same object. In pass-by-value, only a copy is passed, not the object's address. Therefore, the correct answer is Pass-by-reference.
The strategy of allowing processes that are logically runnable to be temporarily suspended is called
A)
Preemptive scheduling
B)
Non-preemptive scheduling
C)
Shortest job first
D)
FCFS
In preemptive scheduling, a process that is logically runnable can be temporarily suspended by the operating system so that another process may run. This is exactly the strategy described in the question. Non-preemptive scheduling does not suspend a running process until it finishes or blocks. Shortest job first and FCFS are scheduling algorithms, but they do not specifically define the temporary suspension of runnable processes.
Pixel mask means
A)
A string containing only 1’s
B)
A string containing only 0’s
C)
A string containing 1 and 0
D)
A string containing 0 and 0
A pixel mask is a binary mask used in computer graphics to select or modify pixels. Since it works in binary form, it consists of 1s and 0s. Option (c) is correct because a mask is represented by a string of 1 and 0. Options (a) and (b) are incorrect because a mask cannot contain only one binary value, and (d) is invalid.
The data structure used for file directory is called
A)
mount table
B)
hash table
C)
file table
D)
process table
A file directory is commonly implemented using a hash table to allow fast lookup of files by name. A hash table maps a file name to its directory entry efficiently. The other options are not used as the standard data structure for file directories: a mount table stores mounted file systems, a file table stores open file information, and a process table stores process information.
Reflection of a point about x-axis, followed by a counter-clockwise rotation of 90º, is equivalent to reflection about the line.
A)
x =−y
B)
x = y
C)
x = 0
D)
y = 0
Let the point be (x, y). Reflection about the x-axis gives (x, -y). A counter-clockwise rotation of 90° maps (u, v) to (-v, u), so (x, -y) becomes (y, x). The transformation (x, y) -> (y, x) is exactly reflection about the line x = y. Hence the correct answer is x = y.
The part of machine level instruction, which tells the central processor what to be done is
A)
Operation code
B)
Address
C)
Locator
D)
Flip-flop
In a machine-level instruction, the **operation code (opcode)** specifies the action the CPU must perform, such as add, subtract, load, or store. The **address** part tells where the data is located, not what operation to do. **Locator** is not a standard part of machine instruction, and a **flip-flop** is a storage element in digital circuits, not an instruction field.
The phenomenon of having a continuous glow of beam on the screen even after it is removed is known as
A)
Fluorescence
B)
Persistence
C)
Phosphorescence
D)
Incandescence
In computer graphics, the continuous glow of a beam on the screen even after the beam is removed is called persistence. It refers to the time for which the screen continues to emit light after excitation. Fluorescence and phosphorescence are related light-emission phenomena in materials, but the standard term used in display technology is persistence. Incandescence means emission of light due to high temperature.
Assume that we have constructor functions for both base class and derived class. Now consider the declaration in main( ). Base * P = New Derived; in what sequence will the constructor be called?
A)
Derived class constructor followed by Base class constructor.
B)
Base class constructor followed by derived class constructor.
C)
Base class constructor will not be called.
D)
Derived class constructor will not be called.
When an object of a derived class is created, the base class part must be constructed first. So in `Base *P = new Derived;`, the actual object is of type `Derived`, and construction happens in this order: first the Base class constructor, then the Derived class constructor. Option (a) is incorrect because derived construction cannot happen before base construction. Options (c) and (d) are incorrect because both constructors are called for a derived object.
Semaphore are used to solve the problems of
A)
Race condition
B)
Process synchronisation
C)
Mutual exclusion
D)
None of these
Semaphores are synchronization primitives used in operating systems to coordinate the execution of concurrent processes/threads. They help control access to shared resources and can be used for mutual exclusion as well, but their primary purpose is process synchronization. Race conditions are prevented through synchronization mechanisms like semaphores, but the broader and most correct answer here is process synchronisation. Hence, option (b) is correct.
The basic attributes of a straight line segment are
A)
Type
B)
Width
C)
Color
D)
All of these
In computer graphics, a straight line segment is commonly described by basic attributes such as its type, width, and color. Since all three are valid attributes, the correct answer is 'All of these'. Options (a), (b), and (c) are each only partially correct.
Which of the following operators cannot be overloaded?
A)
>>
B)
? :
C)
.
D)
Both (b) and (c)
In C++, the conditional operator `?:` and the member access operator `.` cannot be overloaded. The right-shift operator `>>` can be overloaded. Therefore, the correct answer is both (b) and (c).
Which of the following is not a type of constructor?
A)
Copy Constructor
B)
Friend Constructor
C)
Default Constructor
D)
Parameterized Constructor
In object-oriented programming, common types of constructors include Default Constructor, Parameterized Constructor, and Copy Constructor. A 'Friend Constructor' is not a recognized type of constructor in C++ or standard OOP terminology. 'Friend' is a keyword used for friend functions/classes, not constructors.
What is the name of the technique in which the operating system of a computer executes several programs concurrently by switching back and forth between them?
A)
Partitioning
B)
Multitasking
C)
Paging
D)
Timesharing
The technique where an operating system runs several programs concurrently by rapidly switching between them is called multitasking. It gives the illusion that multiple programs are running at the same time. Partitioning is a memory management method, paging is a memory allocation technique, and timesharing specifically refers to sharing CPU time among multiple users/processes, but the general term for running several programs concurrently is multitasking.
Total float for any activity is defined as the difference between
A)
its latest finish time and earliest start time for its successor activity
B)
its latest start time and earliest start time
C)
its latest start time and earliest finish time
D)
its earliest finish time and earliest start time for its successor activity
Total float of an activity is the amount of time by which the activity can be delayed without delaying the project completion time. It is given by: Total Float = Latest Start Time (LST) - Earliest Start Time (EST), or equivalently Latest Finish Time - Earliest Finish Time. Hence option (b) is correct. Option (c) is the formula for free float in some contexts only when expressed differently, and options (a) and (d) do not define total float correctly.
Whenever an activity has zero total float, then
A)
free float of the activity must be zero but independent float need not be zero
B)
independent float must be zero but free float need not be zero
C)
free float and independent float both must be zero
D)
free float and independent float both need not be zero
If an activity has zero total float, it lies on the critical path. For a critical activity, any delay will delay the project, so there is no spare time available. Hence its free float is zero. Since independent float is always less than or equal to free float, it must also be zero. Therefore, both free float and independent float are zero.
The type of footing which is used to transmit heavy loads through steel columns is
A)
raft foundation
B)
grillage foundation
C)
well foundation
D)
isolated footing
Grillage foundation is specifically used to transmit heavy loads from steel columns to the soil by spreading the load over a larger area through layers of steel beams. Raft foundation is used for low bearing capacity soils, well foundation is used for deep foundations in waterlogged areas, and isolated footing is generally used for individual columns but not especially for heavy steel column loads.
The two point problem and three point problem are methods of
A)
resection
B)
orientation
C)
traversing
D)
resection and orientation
The two-point problem and three-point problem are classic methods used in plane table surveying for determining the position of the plane table station. These are treated under resection, and they also involve orientation of the table. Hence, the best answer is 'resection and orientation'. Option (a) is incomplete, while traversing is a different surveying method.
When the speed of traffic flow becomes zero, then
A)
traffic density attains maximum value whereas traffic volume becomes zero
B)
traffic density and traffic volume both attain maximum value
C)
traffic density and traffic volume both become zero
D)
traffic density becomes zero whereas traffic volume attains maximum value
In traffic flow theory, volume (flow) is the number of vehicles passing a point per unit time, and speed is the rate of movement. If speed becomes zero, vehicles are stationary, so no vehicles pass the point per unit time; hence traffic volume becomes zero. At the same time, vehicles can accumulate on the road, so traffic density becomes maximum. Therefore, option (a) is correct. The other options are incorrect because zero speed does not imply zero density, and volume cannot be maximum when vehicles are not moving.
If ‘D’ is the diameter of tunnel in metres, then the thickness of lining in mm, as per the empirical formula is given by
A)
42 D
B)
82 D
C)
104 D
D)
124 D
For tunnel lining, the commonly used empirical formula gives the thickness of lining in millimetres as about 82 times the tunnel diameter in metres. Hence, if D is the diameter of the tunnel, thickness = 82D mm. The other options are not the standard empirical value used in tunnel engineering.
The shape of transition curve used by Indian Railways is
A)
cubic parabola
B)
spiral
C)
sine curve
D)
lemniscate of Bernoulli
In Indian Railways, the standard transition curve adopted is the cubic parabola. It provides a gradual change in curvature from the straight to the circular curve, ensuring smooth vehicle movement and comfort. A spiral is also used in railway engineering in general, but for Indian Railways the commonly specified transition curve shape is the cubic parabola. Sine curve and lemniscate of Bernoulli are not the standard choice here.
The effective height of free standing non load bearing wall and column respectively will be (where H is the height of wall or column between centres of supports)
A)
1.0H and 1.0H
B)
1.5H and l.5H
C)
2.0H and l.5H
D)
2.0H and 2.0H
For a free-standing non-load-bearing wall, the effective height is taken as 2.0H. For a column, the effective height is taken as 1.5H. Here H is the actual height between the centres of supports. Therefore, the correct pair is 2.0H and 1.5H.
Consider the following operations: 1. Drilling, 2. Blasting, 3. Mucking, 4. Placing steel, 5. Placing concrete. The correct sequence of these operations in tunnel construction is
A)
1,2,4,3,5
B)
1,3,2,4,5
C)
1,2,3,4,5
D)
1,3,4,2,5
In conventional tunnel construction, the usual cycle is: drilling the face, blasting to break the rock, mucking to remove the broken material, then placing steel support if required, and finally placing concrete lining. So the correct sequence is 1 → 2 → 3 → 4 → 5. The other options place mucking or support operations before blasting, which is not the correct construction order.
Which of the following lining materials is useful for shield driven tunnels in sub aqueous regions?
A)
stone masonry
B)
timber
C)
cast iron
D)
cement concrete
Shield-driven tunnels in sub-aqueous regions are exposed to high water pressure and require a strong, watertight, and durable lining. Cast iron lining is traditionally used for such tunnels because it can resist heavy external pressure and provides good joint tightness. Stone masonry and timber are not suitable under submerged conditions, and cement concrete is generally less preferred for shield-driven sub-aqueous tunnels compared with cast iron.