BSc CSIT (TU) Science Introduction to Information Technology (BSc CSIT, CSC109) Question Paper 2077 Nepal

Information Technology (IT)

Definition: Information Technology is the use of computers, storage, networking, and other physical devices, infrastructure, and processes to create, process, store, secure, and exchange all forms of electronic data. In short, IT is the combination of computing (hardware and software) and communication technology used to acquire, process, store, and disseminate information.

Applications of IT in Different Fields

1. Education

• E-learning and online classes: Platforms like Zoom, Google Classroom and MOOCs (Coursera, edX) enable distance learning.
• Digital content: E-books, multimedia tutorials, simulations and virtual labs improve understanding.
• Administration: Student records, results, and admissions are managed through information systems.
• Research: Online journals, digital libraries and statistical software aid academic research.

2. Business

• E-commerce: Online buying/selling (Amazon, Daraz) expands markets globally.
• Management Information Systems (MIS) / ERP: Automate accounting, inventory, payroll and decision-making.
• Communication & collaboration: Email, video conferencing and cloud sharing speed up operations.
• Marketing: Digital and social-media marketing target customers precisely.

3. Health

• Electronic Health Records (EHR): Store and retrieve patient data efficiently.
• Telemedicine: Remote diagnosis and consultation over the internet.
• Diagnostic equipment: Computerized devices like MRI, CT scan, and ECG.
• Hospital management systems: Manage appointments, billing and pharmacy.

4. Entertainment

• Digital media: Streaming services (Netflix, YouTube, Spotify) deliver movies, music and games.
• Animation & gaming: Computer graphics, VR and AR create immersive experiences.
• Social media: Facebook, Instagram and TikTok provide interactive entertainment.

Conclusion

IT has become an integral part of every sector, increasing efficiency, accuracy, speed and reach, and transforming the way people learn, work, stay healthy and entertain themselves.

Number Systems Used in Computers

A number system is a way of representing numbers using a set of symbols (digits) and a base (radix). The four common number systems are:

• Binary (base 2): Used internally by digital computers because electronic circuits have two stable states (ON/OFF). All data and instructions are ultimately stored as binary.
• Octal (base 8): A compact form of binary; each octal digit equals 3 binary bits.
• Decimal (base 10): The everyday number system understood by humans.
• Hexadecimal (base 16): A compact form of binary used for memory addresses and machine code; each hex digit equals 4 binary bits.

Conversion of $(256.5)_{10}$

To Binary

Integer part (256): Repeatedly divide by 2 and record remainders.

$$256 \div 2 = 128\ r\ 0$$ $$128 \div 2 = 64\ r\ 0$$ $$64 \div 2 = 32\ r\ 0$$ $$32 \div 2 = 16\ r\ 0$$ $$16 \div 2 = 8\ r\ 0$$ $$8 \div 2 = 4\ r\ 0$$ $$4 \div 2 = 2\ r\ 0$$ $$2 \div 2 = 1\ r\ 0$$ $$1 \div 2 = 0\ r\ 1$$

Reading remainders bottom to top: $256 = (100000000)_2$.

Fractional part (0.5): Multiply by 2 and record carries.

$$0.5 \times 2 = 1.0 \Rightarrow 1$$

So $0.5 = (0.1)_2$.

$$\boxed{(256.5)_{10} = (100000000.1)_2}$$

To Hexadecimal

Integer part (256): Repeatedly divide by 16.

$$256 \div 16 = 16\ r\ 0$$ $$16 \div 16 = 1\ r\ 0$$ $$1 \div 16 = 0\ r\ 1$$

Reading bottom to top: $256 = (100)_{16}$.

Fractional part (0.5): Multiply by 16.

$$0.5 \times 16 = 8.0 \Rightarrow 8$$

So $0.5 = (0.8)_{16}$.

$$\boxed{(256.5)_{10} = (100.8)_{16}}$$

(Check via binary: $100000000.1_2$ grouped in 4-bit nibbles = $0001\ 0000\ 0000\ .\ 1000 = 100.8_{16}$ — confirmed.)

Computer Security

Definition: Computer security (also called cybersecurity) is the protection of computer systems, networks, programs and data from theft, damage, unauthorized access, disruption or misuse. Its goal is to maintain the three core principles known as the CIA triad:

• Confidentiality – information is accessible only to authorized users.
• Integrity – information is accurate and not altered improperly.
• Availability – information and resources are available when needed.

Threats to Computer Security

1. Malware: Malicious software such as viruses, worms, trojan horses, spyware and ransomware that damage or steal data.
2. Hacking / Unauthorized access: Intruders gaining access to systems to steal or alter data.
3. Phishing & Social engineering: Tricking users into revealing passwords or sensitive information.
4. Denial of Service (DoS/DDoS): Overloading a system so legitimate users cannot access it.
5. Data theft / Eavesdropping: Interception of data during transmission.
6. Physical threats: Theft of hardware, fire, power failure or natural disasters.
7. Insider threats: Misuse of access by employees.

Measures to Protect a Computer System

• Antivirus and anti-malware software: Detect and remove malicious programs; keep them updated.
• Firewall: Filters incoming and outgoing network traffic to block unauthorized access.
• Strong authentication: Strong passwords, multi-factor authentication and biometrics.
• Encryption: Encode data so that only authorized parties can read it.
• Regular updates / patching: Fix known vulnerabilities in OS and software.
• Data backup: Maintain regular backups to recover from data loss or ransomware.
• Access control: Grant users only the privileges they need (principle of least privilege).
• Physical security: Locks, surveillance, UPS and controlled access to hardware.
• User awareness: Train users to recognize phishing and follow safe practices.

Conclusion

Computer security combines technical controls, policies and user awareness to safeguard the confidentiality, integrity and availability of information.

Characteristics of a Computer

The main characteristics of a computer are:

1. Speed: A computer processes data extremely fast, performing millions/billions of operations per second (measured in MIPS, nanoseconds/picoseconds).
2. Accuracy: It produces highly accurate, error-free results provided the input and instructions are correct (errors are usually due to human input — GIGO).
3. Diligence: It can perform repetitive tasks tirelessly without fatigue, boredom or loss of concentration.
4. Versatility: A single computer can perform many different types of tasks — calculation, document editing, gaming, communication, etc.
5. Storage capacity: It can store huge amounts of data and retrieve it quickly when required.
6. Automation: Once a program is loaded, it can carry out tasks automatically with little human intervention.
7. Reliability: It gives consistent results over long periods of operation.

Bit, Byte and Word

• Bit: A bit (binary digit) is the smallest unit of data in a computer, having a value of either 0 or 1.
• Byte: A byte is a group of 8 bits. It is the basic unit used to represent a single character (such as a letter, digit or symbol). Memory size is commonly measured in bytes (KB, MB, GB).
• Word: A word is the number of bits a CPU can process or transfer as a single unit at one time (e.g., 16-bit, 32-bit or 64-bit word). The word size depends on the processor architecture.

Firmware

Firmware is a special type of software that is permanently or semi-permanently stored in a hardware device's non-volatile memory (such as ROM, EPROM or flash memory). It provides the low-level control and instructions needed for the device to operate. Examples include the BIOS/UEFI of a computer, and the control programs inside printers, routers and washing machines.

Because firmware sits between hardware and higher-level software, it is often called "software embedded in hardware."

Difference Between Firmware and Software

Working of a Printer

A printer is an output device that produces a hard copy (on paper) of digital information from a computer. Working: The application sends the document to the printer driver, which converts it into a language the printer understands (e.g., PCL or PostScript). The data is sent to the printer's buffer, and the printer's control circuitry then forms the image on paper — either by striking, spraying ink, or fusing toner — line by line or page by page.

Types of Printers

Printers are broadly classified into two categories:

1. Impact Printers

Form characters by striking an inked ribbon against the paper (noisy, can make carbon copies).

• Dot-matrix printer: A print head with pins strikes the ribbon to form characters from a pattern of dots.
• Daisy-wheel / Line printers: Print fully-formed characters or whole lines at a time.

2. Non-Impact Printers

Form characters without physical contact (quieter, higher quality).

• Inkjet printer: Sprays tiny droplets of liquid ink onto the paper through fine nozzles; good for color printing.
• Laser printer: Uses a laser beam to draw the image on a photosensitive drum, which attracts toner powder that is then fused onto the paper by heat; fast and high quality.
• Thermal printer: Uses heat to produce images on special heat-sensitive paper (e.g., receipt printers).

SRAM vs DRAM

Both SRAM (Static RAM) and DRAM (Dynamic RAM) are types of volatile semiconductor memory, but they differ in construction and use.

Summary: SRAM is fast, expensive and used for cache; DRAM is slower, cheaper, denser and used as the computer's main memory.

Client–Server and Peer-to-Peer Network Models

Client–Server Model

In a client–server network, one or more powerful computers (servers) provide resources and services, and other computers (clients) request and use those services. The server centrally manages data, security and resources.

• Examples: Web (browser–web server), email, file servers.
• Advantages: Centralized control, better security, easier backup and management, scalable.
• Disadvantages: Costly (dedicated server needed); if the server fails, services become unavailable.

Peer-to-Peer (P2P) Model

In a peer-to-peer network, all computers (peers) are equal — each can act as both a client and a server, sharing resources directly without a central server.

• Examples: Small home/office LANs, file-sharing networks like BitTorrent.
• Advantages: Cheap and simple to set up, no dedicated server required, no single point of failure.
• Disadvantages: Weak security, harder to manage and back up, poor performance with many users.

E-commerce

E-commerce (Electronic Commerce) is the buying and selling of goods and services, and the transfer of money and data, over electronic networks — primarily the internet. It includes online shopping, electronic payments, online banking, and digital marketing. Examples: Amazon, Daraz, eBay.

Types of E-commerce

1. B2B (Business-to-Business): Transactions between two businesses (e.g., a manufacturer selling to a wholesaler).
2. B2C (Business-to-Consumer): A business sells directly to individual customers (e.g., Daraz, Amazon).
3. C2C (Consumer-to-Consumer): Consumers sell to other consumers through a platform (e.g., eBay, OLX, Hamrobazar).
4. C2B (Consumer-to-Business): Individuals sell products/services to businesses (e.g., a freelancer offering services to a company).
5. B2G / G2C (Business/Consumer-to-Government): Transactions involving government, such as online tax payment and e-governance services.

Components (Elements) of Multimedia

Multimedia is the integration of multiple forms of media — text, graphics, audio, video and animation — into a single interactive application. Its five main components are:

1. Text: The basic element used to convey information, titles, and descriptions. Fonts, sizes and styles affect readability.
2. Graphics (Images): Still pictures such as photographs, drawings, charts and icons (e.g., JPEG, PNG, GIF) that make content visually appealing.
3. Audio (Sound): Speech, music and sound effects (e.g., MP3, WAV) that enhance the user's experience.
4. Video: Moving images with sound (e.g., MP4, AVI) used to demonstrate real-life scenes and processes.
5. Animation: Computer-generated moving graphics created by displaying a sequence of images rapidly, used for simulations, cartoons and visual effects.

Often interactivity (user control through hyperlinks, buttons and navigation) is also listed as an essential element that distinguishes multimedia from ordinary media.

Antivirus Software

Antivirus software is a utility program designed to detect, prevent and remove malicious software (malware) such as viruses, worms, trojans, spyware and ransomware from a computer system.

How it works

• Signature-based detection: Compares files against a database of known virus signatures (patterns).
• Heuristic / behavior-based detection: Identifies new or unknown threats by analyzing suspicious behavior or code patterns.
• Real-time scanning: Continuously monitors files, downloads and emails as they are accessed.
• Quarantine and removal: Isolates or deletes infected files to stop them spreading.

Key features

• Regular virus-definition updates to recognize the latest threats.
• Scheduled and on-demand scans of the full system or specific files.
• Web, email and download protection.

Examples

Kaspersky, Avast, AVG, Norton, McAfee, Bitdefender, Windows Defender.

Importance: Antivirus software protects data integrity and privacy, prevents system damage and keeps the computer running safely. It must be kept updated to remain effective.