Q1. (a) State True or false-

( i) ROM is a volatile memory.

(ii) A network is interconnection of computers that enables  the users to share network resources.

(iii) A foreign key always uniquely identifies a record.

(iv) Chart crated on the worksheet is called embedded charts

(B) Answer in one line:

(i)  Define topology.

(il) What is folder?

(il) What is the use of random sampling?

Answers.

(a) State True or False:

(i) False. ROM (Read-Only Memory) is a non-volatile memory, meaning its contents are retained even when power is turned off.

(ii) True. A network is an interconnection of computers that enables users to share network resources such as data, files, printers, etc.

(iii) False. A foreign key may or may not uniquely identify a record, as it refers to the primary key of another table and may have duplicate values in the referencing table.

(iv) True. Charts created on a worksheet in a spreadsheet software are commonly referred to as embedded charts, as they are integrated within the worksheet itself.

(B) Answer in one line:

(i) Topology refers to the physical or logical layout of a computer network.

(ii) A folder is a directory or container used to store files and other folders in a hierarchical manner on a computer’s file system.

(iii) Random sampling is used in statistics and research to select a random subset of individuals or data points from a larger population for analysis or study.

Q2. What do you understand by network topology? Describe three commonly used network topology .

Ans. Network topology refers to the physical or logical layout of a computer network, which determines how devices such as computers, switches, routers, and servers are interconnected. There are various types of network topologies, and three commonly used ones are:

Bus Topology: In a bus topology, all devices in a network are connected to a single communication channel, which acts as a shared medium. Each device has its own unique address, and data is transmitted in both directions along the bus. However, when two devices transmit data simultaneously, a collision may occur, leading to data loss or corruption. Bus topology is simple and inexpensive to implement, but it can suffer from performance degradation and is not widely used in modern networks.

Star Topology: In a star topology, all devices in a network are connected to a central device, such as a switch or a hub. The central device acts as a point of connection for all devices and manages the flow of data between them. Each device in a star topology has its own dedicated connection to the central device, which eliminates the risk of collisions. Star topology is widely used in Ethernet networks and is easy to manage, but it requires more cabling and can suffer from a single point of failure if the central device fails.

Mesh Topology: In a mesh topology, all devices in a network are interconnected with each other, forming multiple redundant paths for data transmission. Each device in a mesh topology can communicate directly with any other device, creating a highly resilient and fault-tolerant network. Mesh topology provides high scalability and reliability, but it requires more cabling and is more complex to manage.

Other common network topologies include ring topology, tree topology, and hybrid topology, which combine different types of topologies. The choice of network topology depends on various factors such as the size of the network, the required level of redundancy, the cost of implementation, and the type of data transmission requirements.

OR

Q2. What is a Payment Gateway? How it works?

Ans. A payment gateway is a technology solution that enables online merchants to securely accept and process electronic payments from customers for goods and services purchased online. It acts as an intermediary between the customer, the merchant, and the financial institutions involved in the payment process, such as banks and credit card companies.

The process of how a payment gateway works can be summarized as follows:

Customer places an order: The customer selects products or services on the merchant’s website and proceeds to the checkout page to initiate the payment process.

Payment information is entered: The customer enters payment information, such as credit card details, into the checkout page. The payment gateway encrypts the payment data to ensure it is transmitted securely over the internet.

Payment data is transmitted: The encrypted payment data is transmitted from the merchant’s website to the payment gateway for processing.

Payment authorization: The payment gateway verifies the payment information with the respective financial institution, such as the customer’s bank or credit card company, to ensure the payment details are valid and that the customer has sufficient funds or credit to complete the transaction.

Transaction approval or decline: The financial institution sends a response to the payment gateway indicating whether the transaction is approved or declined. The payment gateway then relays this information to the merchant’s website.

Confirmation to customer: The customer receives a confirmation or decline notification on the merchant’s website, indicating the outcome of the transaction.

Settlement and funds transfer: If the transaction is approved, the payment gateway initiates the settlement process, where the funds from the customer’s account are transferred to the merchant’s account. This process may involve additional steps, such as clearing and settlement with the respective financial institutions, depending on the payment method used.

Transaction record keeping: The payment gateway typically maintains a record of all transactions processed, including transaction details, payment data, and authorization responses, for record-keeping, reconciliation, and dispute resolution purposes.

Overall, a payment gateway provides a secure and efficient way for online merchants to accept and process electronic payments, ensuring that sensitive payment information is transmitted and stored securely, and that transactions are authorized and settled accurately.

Q3. How traditional file system is different from database system?

Ans. A traditional file system and a database system are two different approaches to organizing and managing data. Here are some key differences between the two:

Data Structure: In a traditional file system, data is stored in separate files, each with its own structure and format. There may be redundancy and inconsistency in data across different files, and data relationships may not be well-defined. In contrast, a database system uses a centralized and structured approach to store data in a database, with a defined data model (such as a relational, hierarchical, or object-oriented model) that establishes relationships between data entities.

Data Integrity: In a traditional file system, data integrity (i.e., accuracy, consistency, and reliability of data) relies on manual checks and validations, which can be prone to errors. In a database system, data integrity is maintained through built-in mechanisms such as constraints, triggers, and rules that ensure data consistency, enforce data integrity rules, and prevent data duplication or inconsistency.

Data Sharing and Accessibility: In a traditional file system, data is typically stored in separate files, and sharing or accessing data across multiple applications or users can be challenging. In a database system, data can be easily shared and accessed by multiple applications or users concurrently, with proper access controls and permissions.

Data Scalability and Flexibility: In a traditional file system, adding, modifying, or deleting data may require changes to multiple files and programs, making it less scalable and flexible. In a database system, data can be easily modified, updated, or deleted using standardized database operations, making it more scalable and flexible in handling changing business requirements.

Data Management and Administration: In a traditional file system, data management and administration tasks such as data backup, recovery, security, and maintenance are typically performed manually, which can be time-consuming and error-prone. In a database system, these tasks can be automated and managed through a centralized database management system (DBMS), which provides tools and features for efficient data management, backup, recovery, and security.

Data Consistency and Redundancy: In a traditional file system, data redundancy and inconsistency may occur due to the lack of central control and standardization, resulting in duplicate data and potential data integrity issues. In a database system, data redundancy can be minimized through normalization techniques, and data consistency is maintained through proper data management practices, such as transaction management and concurrency control.

Overall, a database system provides a more structured, efficient, and scalable approach to managing and organizing data compared to a traditional file system, which may be more manual, error-prone, and less flexible in handling data-related tasks.

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Q3. What is operating system (OS)? Explain the types of operating system based on processing capability.

Ans. An operating system (OS) is a software program that manages and controls the hardware resources of a computer system, and provides a convenient and efficient interface for users to interact with the computer and run applications.

Based on processing capability, operating systems can be categorized into the following types:

Single-user, single-tasking OS: This type of operating system allows only one user to run one task or application at a time. Examples include older versions of MS-DOS (Microsoft Disk Operating System) and early versions of Apple Macintosh OS.

Single-user, multi-tasking OS: This type of operating system allows a single user to run multiple tasks or applications concurrently, where each task or application runs in the background and appears to be executing simultaneously. Examples include modern versions of Microsoft Windows, MacOS, and Linux.

Multi-user OS: This type of operating system allows multiple users to run multiple tasks or applications concurrently, where each user can have their own user account with separate settings, privileges, and resources. Examples include server operating systems such as Windows Server, Linux distributions for servers, and mainframe operating systems like IBM z/OS.

Real-time OS: This type of operating system is designed to handle real-time applications that require immediate and deterministic responses to external events. Real-time operating systems are used in embedded systems, industrial control systems, and other time-sensitive applications where the system must respond to events in real-time without delays. Examples include VxWorks, QNX, and FreeRTOS.

Distributed OS: This type of operating system is designed to manage and coordinate the resources of a network of interconnected computers, allowing them to work together as a single system. Distributed operating systems are used in large-scale distributed computing environments such as cloud computing, grid computing, and cluster computing. Examples include Google’s Android (for mobile devices) and distributed versions of Linux such as Red Hat Enterprise Linux (RHEL) and Ubuntu Server.

These are some common types of operating systems based on processing capability. Each type of operating system has its own features, advantages, and use cases, depending on the requirements of the computer system or application it serves.

Q4. Explain the following with example:

(i) Primary Key

(ii) Alternate key

(ili) Secondary Key

Ans.  (i) Primary Key: In a relational database, a primary key is a unique identifier for a record or row in a table. It uniquely identifies each record in the table and ensures that each record has a unique identity. A primary key must have the following properties:

Unique: No two records in the table can have the same primary key value.

Non-null: A primary key value cannot be null or empty.

Stable: A primary key value should remain unchanged over the lifetime of the record.

Example: Consider a “Students” table in a database with the following fields: StudentID (primary key), Name, Age, and Grade. In this case, the StudentID field serves as the primary key, uniquely identifying each student record in the table.

(ii) Alternate Key: An alternate key is a candidate key that is not chosen as the primary key for a table. It is also unique and can uniquely identify each record in the table, but it is not selected as the primary key. A table can have multiple alternate keys.

Example: Continuing with the “Students” table example, if in addition to the StudentID, both the Name and the Email fields are also unique and can identify each student record, then Name and Email could be alternate keys in the table.

(iii) Secondary Key: A secondary key is a key that is used for data retrieval or indexing purposes, but it is not unique. Unlike primary and alternate keys, a secondary key may have duplicate values. Secondary keys are used to speed up data retrieval operations and improve query performance.

Example: In the “Students” table, if there is a field called Grade, which represents the grade level of the student, and multiple students can have the same grade, then Grade could be used as a secondary key. It can be used to quickly retrieve all the students belonging to a particular grade level without enforcing uniqueness.

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Q4. What is DBMS? Explain its advantages and limitations?

Ans. DBMS stands for Database Management System, which is a software application that enables users to interact with a database and manage its data. It provides an organized and systematic way of storing, managing, and retrieving data in a database.

Advantages of DBMS:

Data Integrity: DBMS enforces integrity constraints to ensure that data entered into the database is accurate and consistent. It prevents data duplication, maintains referential integrity, and allows for data validation, thereby improving data quality and reliability.

Data Security: DBMS provides mechanisms to define access controls, authentication, and authorization to protect data from unauthorized access, modification, or deletion. It allows for user-level security, role-based permissions, and encryption, enhancing data security and confidentiality.

Data Consistency and Centralized Management: DBMS provides a centralized system for managing data, ensuring that data is consistent across different applications and users. It eliminates data redundancy and inconsistencies, which reduces the chances of data discrepancies and improves data integrity.

Data Sharing and Concurrent Access: DBMS allows for concurrent access to the database by multiple users or applications, enabling data sharing and collaboration among different users or departments. It provides mechanisms for concurrency control and transaction management, ensuring data integrity and consistency in a multi-user environment.

Data Backup and Recovery: DBMS provides features for data backup, recovery, and disaster management. It allows for scheduled backups, point-in-time recovery, and transaction log management, which helps in protecting data from accidental loss, hardware failures, or disasters.

Limitations of DBMS:

Cost and Complexity: DBMS software can be expensive to acquire, implement, and maintain. It requires skilled personnel for administration, configuration, and maintenance, which adds to the overall cost and complexity of the system.

Performance Overhead: DBMS introduces some performance overhead due to its additional layers of abstraction, data modelling, and processing. Complex queries or transactions may require additional processing time, which can affect system performance.

Scalability and Flexibility: DBMS may have limitations in terms of scalability and flexibility, especially with regards to handling large volumes of data or accommodating changes in data structures or business requirements. Upgrading or modifying a DBMS can be complex and time-consuming.

Dependence on DBMS Vendor: Organizations using a particular DBMS may become dependent on the vendor for support, upgrades, and bug fixes. Switching to a different DBMS may involve migration efforts and potential compatibility issues.

Security Risks: While DBMS provides data security features, it is still vulnerable to security risks such as SQL injection attacks, unauthorized access, or insider threats. Organizations need to implement additional security measures to protect against these risks.

In summary, DBMS offers many advantages in terms of data integrity, security, consistency, sharing, and recovery. However, it also has limitations in terms of cost, complexity, performance overhead, scalability, and dependence on vendors. Organizations need to carefully evaluate their requirements and considerations before choosing and implementing a DBMS.