CS Free MCQ Bank

[ Option C ]

The architectural design provides a high-level view of system components and their interactions.

[ Option B ]

Cohesion refers to how closely the elements within a single module of a program are related to one another. The higher the cohesion, the better the design, as the module performs a single, well-defined task. Different types of cohesion describe different levels of relationship among module elements.

• Best Type : Functional Cohesion.
• Worst Type : Co-incidental Cohesion.

QUALITY ORDER FROM WORST TO BEST:
Co-incidental → Logical → Temporal → Procedural → Communicational → Sequential → Functional.

[ Option D ]

A Decision Table is a tabular method for representing logical relationships between conditions and actions in a system. It is widely used in software testing, system design, and decision-making.

[ Option C ]

A Data Dictionary is a centralized, structured repository that contains metadata, information about the data used in a system, such as:

• Names of data elements.
• Data types and formats.
• Relationships between data items.
• Default values or constraints.

[ Option A ]

When a big program becomes too large to understand, we divide it into small manageable modules. To show how these modules are arranged and how they communicate, we use a special tool called a Structure Chart.
It looks like a Tree Diagram where the top represents the main module and the bottom branches represent submodules.

• So, a Structure Chart is the program development tool that graphically shows how a program is divided into modules, their hierarchy, organization, and communication.

[ Option B ]

An ACD (Architectural Context Diagram) provides a high-level view of the system and shows how it fits into its environment. It illustrates the system boundary and depicts all external interfaces through which the system communicates with other entities.

This helps designers and stakeholders understand what lies inside and outside the system’s scope, ensuring that all necessary interactions are properly identified and managed.

[ Option A ]

Data Flow Diagrams (DFDs) are used to represent how data moves through a system. A Context Diagram is the highest-level view of a DFD, which provides an overview of the entire system as a single process.
Because it gives this top-level, overall picture without showing internal details, the Context Diagram is also called a Level 0 DFD.

Lower-level DFDs such as Level 1, Level 2, and so on, break this single process into smaller sub-processes, showing more internal details of how the system functions.

[ Option B ]

Cohesion refers to the degree of relatedness and functional strength of the elements within a single module. It indicates how well the parts of a module work together to achieve a specific purpose.
High cohesion means that all parts of the module are closely related and focused on a single task, which leads to more maintainable, understandable, and reliable software.

• Cohesion tells how strongly the parts of a module are related to each other.
• Higher cohesion means stronger, better, and more focused module.

[ Option A ]

A Data Flow Diagram (DFD) is a visual representation that depicts the flow of information and the transformations applied to data as it moves from input to output in a system. It graphically shows how data enters the system, the processes that act on the data, where the data is stored, and how it exits the system.

[ Option B ]

The Open-Closed Principle (OCP) is one of the key object-oriented design principles. It states that a software component such as a class, module, or function should be open for extension but closed for modification. This means that the behavior of a component can be extended without altering its existing source code.

[ Option B ]

The low coupling and high cohesion make modules independent and maintainable, improving overall software design quality.

[ Option D ]

The Activity Diagrams model the dynamic behavior of a system and represent workflows of actions and activities.

[ Option B ]

Software design plays a crucial role in ensuring the Quality of software systems. A good design makes software more understandable, maintainable, reliable, and reusable. It reduces development time and effort by providing a clear blueprint before coding begins.

Software design is the foundation of software quality. It influences not only the immediate development but also the long-term success of the system by affecting maintainability, usability, performance, reliability, scalability, and reusability.

[ Option C ]

Before designing a system, we must clearly understand, what the system should do, what features it must have and what limitations and rules apply. These details are called System Requirements.
System Design is the phase in system development that follows requirements analysis. It begins as soon as the system requirements are clearly determined and understood. The purpose of system design is to create the blueprint or architecture of the system that will fulfill those requirements.
Why Design Starts After Final Approval?

• System design needs time, money, and technical planning. So, the analyst waits until management checks, verifies, and approves the final specifications.
• Only then can design begin because now the requirements are fixed and agreed upon.

[ Option D ]

In object-oriented programming, coupling refers to the level of dependency between classes or modules.
High Coupling means a class depends heavily on other classes, which makes the system harder to maintain or modify.
Low Coupling means a class has little knowledge of other classes, leading to more modular and flexible code.

• Coupling measures interconnections between modules or classes.
• Ideal design aims for low coupling to improve maintainability.
• It is different from Cohesion, which measures how closely related the tasks within a single class or module are.

[ Option A ]

In software design, Coupling refers to the degree of interdependence between software modules. Means, how closely connected or dependent one module is on another. It is desirable to have the lowest possible coupling because loosely coupled modules can function independently, are easier to Test, Maintain, and Modify without affecting other parts of the system.

[ Option C ]

A Decision Table is a tabular method for representing logical relationships between conditions and actions in a system. It is widely used in software testing, system design, and decision-making.

[ Option B ]

In a Data Flow Diagram (DFD), a Black Hole is a process or data store that receives data but does not produce any output. In other words, information flows into it, but nothing comes out. This situation usually indicates an error or a missing component in the diagram, as every process should normally transform or pass on data through both input and output flows.

Apart from a Black Hole, there are several other common errors in Data Flow Diagrams (DFD):

[ Option B ]

The main intent of information hiding is to protect the internal details of a module, such as data structures and algorithms. 
By hiding the internal implementation, changes made inside a module do not affect other modules that depend on it. This leads to better modularity, maintainability, and security of the software.

[ Option D ]

In software engineering, interface design focuses on defining how different parts of a system interact with each other and with external entities. It ensures smooth communication between components, users, and external systems. The main elements of interface design include, User Interface (UI), External Interfaces, and Internal Interfaces.
The Modularity refers to the division of a system into smaller, independent components  or modules to improve maintainability, reusability, and clarity.