Computer

Nepal Rastra Bank — Assistant (Level 2)

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1. Applications of an Office System in an Organization — [3 marks]

An office system (office automation system) uses computers, software and communication networks to carry out routine office work efficiently. Its main applications in an organization are:

1. Document preparation and processing — Typing, editing, formatting, storing and printing of letters, reports, notices, circulars and memos using word processing software.
2. Data and record management — Maintaining employee records, payroll, accounts, inventory and customer details in databases and spreadsheets.
3. Communication — Sending and receiving messages, files and notices through e-mail, fax, video conferencing and internal networks.
4. Scheduling and time management — Preparing calendars, fixing meetings, setting reminders and managing appointments electronically.
5. Accounting and financial work — Preparing bills, vouchers, budgets, salary sheets and financial statements quickly and accurately.
6. Storage and retrieval of records — Keeping documents in digital form so that they can be searched and retrieved instantly.
7. Reproduction of documents — Photocopying, scanning and bulk printing of office documents.

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2. Two Major Functions of an Operating System — [2 marks]

An operating system (OS) is system software that acts as an interface between the user and the computer hardware. Two of its major functions are:

(a) Process (Job) Management The OS decides which program will run, when it will run and for how long. It creates, schedules and terminates processes, allocates CPU time among them, and handles the switching between programs so that many jobs can be carried out smoothly. It also detects and resolves deadlock among processes.

(b) Memory Management The OS keeps track of every part of main memory — which portion is free and which is occupied by which program or data. It allocates memory to programs when required, reclaims it when the program ends, and uses techniques such as virtual memory and paging when the physical memory falls short.

(Other functions that may also be mentioned: file management, device/device-driver management, security and access control, user interface provision, error detection.)

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3. Explanation of the Two Major Functions — [5 marks]

(a) Process Management

A process is a program in execution. Several programs may be present in memory at the same time, but a single CPU can execute only one at a time. The operating system manages this whole activity through the following sub-functions:

• Process creation and termination — The OS creates a process when a program is loaded, assigns it a Process Control Block (PCB) containing its ID, state, program counter and register contents, and releases all resources when the process finishes.
• Process scheduling — The OS uses scheduling algorithms (FCFS, SJF, Round Robin, Priority) to select the next process for the CPU. This keeps the CPU busy and gives every process a fair share of processor time.
• Process synchronization — When two or more processes share data or resources, the OS coordinates them using semaphores, locks and monitors so that the shared data does not become inconsistent.
• Inter-process communication — The OS allows processes to exchange data through shared memory or message passing.
• Deadlock handling — If processes wait endlessly for one another's resources, the OS prevents, avoids, detects or recovers from the deadlock.

Example: In a bank's computer, the interest-calculation program, the printing of statements and the cashier's terminal program all run "together". The OS switches the CPU among them so rapidly that each user feels the computer is working only for him.

(b) Memory Management

Main memory (RAM) is limited and must be shared among the OS itself and all running programs. The OS performs the following sub-functions:

• Keeping track of memory — It maintains a record of which memory locations are allocated and to which process, and which are free.
• Allocation and de-allocation — When a program is loaded, the OS reserves the required space; when the program ends, the space is released for reuse. It may use contiguous allocation or paging/segmentation.
• Protection — Each process is given its own protected area so that one program cannot read or overwrite another program's data or the OS itself.
• Virtual memory — When RAM is insufficient, the OS moves inactive pages to the hard disk (swap space) and brings them back when needed. This lets the computer run programs larger than the available physical memory.
• Address translation — It converts the logical address used by the program into the physical address of the memory chip, with the help of the Memory Management Unit (MMU).

Example: A computer with 4 GB RAM can run a program requiring 6 GB of data because the OS keeps the extra portion on the disk and swaps pages in and out as needed.

Measures for IT security in an organization

IT security (also called cyber security) means protecting an organization's computers, networks, data and information systems from theft, damage, unauthorized access, and disruption. The following measures may be adopted:

1. Access control measures

• Strong password policy — long, complex passwords changed periodically; no sharing of passwords.
• Two-factor authentication (2FA) / multi-factor authentication for logins.
• Role-based access control (RBAC) — users get only the access needed for their job (principle of least privilege).
• Biometric authentication (fingerprint, face recognition) for sensitive systems.
• Automatic screen lock and logout after a period of inactivity.

2. Network security measures

• Firewalls (hardware and software) to filter incoming and outgoing traffic.
• Intrusion Detection and Prevention Systems (IDS/IPS).
• Virtual Private Network (VPN) for secure remote access.
• Network segmentation and a demilitarized zone (DMZ) for public-facing servers.
• Secure Wi-Fi with strong encryption (WPA2/WPA3) and MAC address filtering.
• Disabling unused ports, services, and default accounts.

3. Data security measures

• Encryption of data at rest and in transit (e.g., SSL/TLS, AES).
• Regular and tested data backups kept at an off-site location.
• Data classification (public, internal, confidential, secret) with handling rules.
• Data loss prevention (DLP) tools and secure disposal/destruction of old media.

4. Endpoint and system security

• Updated antivirus, anti-malware, and anti-spyware software on all devices.
• Regular patching and updating of operating systems and applications.
• Application whitelisting and endpoint detection and response (EDR).
• Hardening of servers and disabling unnecessary software.

5. Physical security measures

• Restricted entry to server rooms and data centres (locks, access cards, biometrics).
• CCTV surveillance, security guards, and visitor logs.
• Fire suppression systems, UPS, and protection against flood, theft and sabotage.
• Locking of laptops, cabinets for storage media, and clean-desk policy.

6. Administrative and policy measures

• A written IT security policy approved by top management.
• Separation of duties and rotation of duties for sensitive posts.
• Background verification of employees and confidentiality/non-disclosure agreements.
• Regular IT security awareness training and phishing drills for staff.
• Incident response plan, disaster recovery plan, and business continuity plan.

7. Monitoring, audit and compliance measures

• Logging and monitoring of system activities; review of audit logs.
• Periodic security audits, vulnerability assessment, and penetration testing.
• Compliance with standards such as ISO/IEC 27001 and legal requirements of Nepal (e.g., Electronic Transactions Act, 2063).

8. Other technical measures

• Use of licensed and genuine software only.
• Patch management and configuration management systems.
• Email filtering, spam blocking, and protection against social engineering.
• Secure disposal of e-waste and proper media sanitization.

Conclusion IT security is not a one-time task but a continuous process. A combination of technical controls (firewall, encryption, antivirus), physical controls (access control, CCTV), and administrative controls (policy, training, audit) is required to protect the confidentiality, integrity, and availability of organizational information.

Operating System (OS)

An Operating System (OS) is a system software that acts as an intermediary between the user and the computer hardware. It manages all hardware and software resources of a device and provides an environment in which application programs can run. Examples include Windows, Linux, macOS, Android and iOS.

Major roles played by an OS in electronic devices

1. Process Management – The OS creates, schedules, suspends and terminates processes. It allocates CPU time among competing programs (e.g., multitasking in Windows or Android) so that many tasks appear to run simultaneously.

2. Memory Management – It keeps track of every byte of main memory, allocates memory to programs when needed, frees it when no longer required, and uses techniques such as paging and virtual memory to run programs larger than physical RAM.

3. File and Storage Management – The OS organizes data into files and directories, controls reading/writing on hard disks, SSDs and pen drives, and enforces access permissions so that one user's data is protected from another.

4. Device / I/O Management – Through device drivers, the OS controls input and output devices such as keyboard, mouse, printer, camera and network card, buffering and scheduling their requests so that the CPU is not wasted waiting for slow devices.

5. Resource Allocation and Scheduling – It decides which process gets which resource and for how long, using scheduling algorithms (FCFS, Round Robin, Priority) to ensure fair, efficient and timely use of the CPU and other resources.

6. Security and Protection – The OS authenticates users (passwords, PIN, biometrics), isolates processes from one another, and prevents unauthorized access to files, memory and hardware, thereby protecting the device from malware and misuse.

7. User Interface – It provides a CLI (command line) or GUI (windows, icons, menus, pointer) so that the user can interact with the device easily. In mobile devices it also manages touch input and notifications.

8. File System, Networking and Error Handling – It detects and reports errors (e.g., "printer not found"), manages network connections, and maintains system logs, helping the device run reliably.

Conclusion – In every electronic device — from a smartphone to a laptop, ATM or smart TV – the OS is the master control program that coordinates hardware, software and the user, without which the device cannot function usefully.

Database Management System (DBMS)

A Database Management System (DBMS) is a software package that is used to create, store, organize, retrieve, update, and manage data in a database. It acts as an interface between the user (or application program) and the database, so that users do not have to deal with the physical storage of data. It also provides security, integrity, and concurrent access control. Examples: MySQL, Oracle, Microsoft SQL Server, PostgreSQL, MS Access.

Advantages of DBMS over a traditional filing system

1. Controlled redundancy: In a filing system the same data is often stored in many separate files, causing duplication. A DBMS stores data in a centralized database, so duplication is minimized and controlled.
2. Data consistency and integrity: Because data is kept in one place and rules (constraints) can be applied, conflicting copies are avoided. A filing system easily develops inconsistent data when one file is updated and another is not.
3. Data sharing: Many users and applications can use the same database simultaneously, whereas separate files usually belong to one department and cannot be shared easily.
4. Data security: A DBMS provides user accounts, passwords, and privileges (grant/revoke), so only authorized users can access particular data. Files on disk can be read or altered by anyone who has access to the storage.
5. Concurrent access and recovery: A DBMS allows multiple users to work at the same time without corrupting data, and it can restore the database after a failure using backup and log files. A filing system has no such control.
6. Data independence: The logical view of data is separated from its physical storage. The storage structure can be changed without changing the application programs, which is not possible in a filing system.
7. Efficient query and reporting: Data can be searched, filtered, sorted, and summarized quickly using query languages such as SQL, and reports can be generated easily. In a filing system, separate programs must be written for each new report.
8. Reduced cost of maintenance and standardization: Central control enforces common standards for data naming, format, and storage, and reduces the overall cost of storing and maintaining data.

Intranet, Internet and Extranet

Conclusion: The internet is a public global network; an intranet is its private, organisation-only version; and an extranet is a controlled extension of the intranet to trusted outside parties.