← MES Jr. Grade
Past Questions
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.
A system program that combines the separately compiled modules of a program into a form suitable for execution
A)
Assembler
B)
Linking loader
C)
Cross compiler
D)
None of these
A linking loader takes separately compiled object modules, links them together, resolves external references, and loads the combined program into memory in executable form. An assembler translates assembly language into machine code, and a cross compiler compiles code for a different target machine. Therefore, the correct answer is Linking loader.
A process control block does not contain
A)
Program counter
B)
Bootstrap program
C)
Stack
D)
Code
A Process Control Block (PCB) stores information needed to manage a process, such as the program counter, CPU registers, process state, scheduling information, and memory-management details. It may also be associated with stack-related information. The bootstrap program is not part of a PCB; it is a system startup program used to initialize the computer and load the operating system.
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.
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).
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.
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 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.
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.
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.
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.
An object is
A)
a variable of class datatype.
B)
same as a class.
C)
just like a global variable.
D)
collection of data-members and member functions.
In object-oriented programming, a class is a blueprint, and an object is an instance of that class. So an object can be thought of as a variable of class datatype. Option (b) is wrong because a class and an object are not the same. Option (c) is wrong because an object is not a global variable. Option (d) describes a class, not an object.
Hue of a color is related to
A)
Luminance
B)
Saturation
C)
Wavelength
D)
None of these
Hue refers to the basic color type, such as red, green, or blue, and is determined by the dominant wavelength of light. Luminance describes brightness, and saturation describes the purity or intensity of a color. Therefore, hue is related to wavelength.
The LRU algorithm pages out page
A)
That have been used recently
B)
That have not been used recently
C)
That have least used recently
D)
None of these
LRU stands for Least Recently Used. In page replacement, it removes the page that has not been used for the longest time, i.e., the page least recently referenced. So the correct choice is the one saying pages that have not been used recently. Option (a) is the opposite, and (c) is poorly worded but not the standard definition.
To have a pointer to class member it must be declared as
A)
Public
B)
Private
C)
Protected
D)
All of these
A pointer to a class member can be formed for members with any access specifier: public, private, or protected. Access control affects whether you can use the member from outside the class, but it does not prevent the member from being declared or having its address taken in the appropriate context. Therefore, the correct option is 'All of these'.
Which type data structure is used for efficient implementation of scan-line algorithm to fill regions?
A)
Node list
B)
Edge list
C)
Stack
D)
None of these
In the scan-line polygon fill algorithm, an edge list is used to store and process the polygon edges efficiently. It helps quickly determine which edges intersect the current scan line and supports fast filling of regions. A node list is not the standard structure for this purpose, and a stack is not used for the core scan-line filling process.
Vector graphics is composed of
A)
Pixels
B)
Paths
C)
Palette
D)
All of these
Vector graphics are made up of mathematical descriptions of shapes such as lines, curves, and polygons, which are represented as paths. Pixels are the basic unit of raster graphics, not vector graphics. A palette refers to a set of colors, not the structure of vector images. Therefore, the correct answer is Paths.
A direct method of deadlock prevention is to prevent the occurrences of
A)
Mutual exclusion
B)
Hold and wait
C)
Circular waits
D)
No preemption
Deadlock can occur only if all four Coffman conditions hold: mutual exclusion, hold and wait, no preemption, and circular wait. A direct method of deadlock prevention is to break one of these conditions. Preventing circular wait is the most direct method, usually by imposing an ordering on resource requests. The other options are also deadlock conditions, but the standard direct prevention method referred to in such questions is circular wait.
Default constructor has
A)
Single argument
B)
Multiple arguments
C)
No argument
D)
Cannot say
A default constructor is a constructor that can be called without passing any arguments. In object-oriented programming, if no constructor is defined, many languages provide a default no-argument constructor. Therefore, the correct answer is 'No argument'. Options (a) and (b) describe parameterized constructors, and (d) is incorrect because the definition is specific.
A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem.
A)
One
B)
Two
C)
Three
D)
Four
To solve the critical section problem, processes need at least one shared variable (such as a lock, turn variable, or flag) to coordinate entry into the critical section. With one properly shared synchronization variable, mutual exclusion can be enforced. Therefore, the minimum required is one variable. The other options are not minimum requirements.
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.
The amount of light emitted by the phosphor coating depends on the
A)
Number of electrons striking the screen
B)
Speed of electrons striking the screen
C)
Distance from the cathode to the screen
D)
None of these
In a CRT display, the phosphor coating glows when struck by electrons. The brightness of the emitted light depends mainly on how many electrons hit the screen: more electrons produce more light. The speed of electrons affects their energy, but in standard computer graphics MCQs, the expected answer is the number of electrons striking the screen. Distance from the cathode to the screen is not the direct factor.
The address of a page table in memory is pointed by
A)
stack pointer
B)
page table base register
C)
page register
D)
program counter
In paging, the page table is stored in main memory, and its starting address is kept in the Page Table Base Register (PTBR). The CPU uses this register to locate the page table for address translation. The other options are unrelated: the stack pointer points to the top of the stack, the program counter holds the next instruction address, and 'page register' is not the standard register used for page table address.
Frame Buffer is also known as
A)
Refresh Buffer
B)
Memory Buffer
C)
Both (a) and (b)
D)
None of these
A frame buffer stores the pixel values for the image currently being displayed on the screen, and it is also called a refresh buffer because the display is continuously refreshed from this memory. Option (b) is not the standard term, so the correct answer is (a).