CS‑03 : Computer Fundamentals and Emerging Technology

Answer: A computer is an electronic device that accepts data as input, processes it according to a stored set of instructions (a program), and produces information as output; it can also store data for later use. Its six main characteristics are: Speed (executes millions of instructions per second — e.g. calculating the average of 40 students' marks instantly), Accuracy (gives error‑free results if the input and program are correct), Diligence (performs the millionth calculation exactly as accurately as the first, without fatigue), Storage (can permanently hold huge volumes of data in secondary storage such as a hard disk), Versatility (the same hardware can run a game, a spreadsheet, or a banking application), and Automation (once started, a program runs through to completion without step‑by‑step manual intervention).

Answer: Computers have evolved through five generations. 1st Generation (1940–56) used bulky, heat‑generating vacuum tubes and machine language, e.g. ENIAC and UNIVAC. 2nd Generation (1956–63) replaced tubes with smaller, cooler transistors and introduced assembly language. 3rd Generation (1964–71) packed many transistors onto Integrated Circuits (ICs), and keyboards/monitors became standard. 4th Generation (1971–2010) used microprocessors (VLSI chips), giving birth to personal computers, GUIs, the mouse and the internet. 5th Generation (2010–present) uses ULSI chips and focuses on Artificial Intelligence, voice recognition, and parallel processing. Each step made computers smaller, faster, cheaper and more power‑efficient.

Answer: RAM (Random Access Memory) is volatile — it loses its content the moment power is switched off — and it is both readable and writable, used as the computer's temporary working memory (types include SRAM, DRAM, DDR). ROM (Read Only Memory) is non‑volatile — it retains data even without power — and is mostly read‑only, used to permanently store instructions such as the BIOS (types include PROM, EPROM, EEPROM).

Answer: Based on the type of data processed, computers are of three kinds: Analog computers process continuous physical quantities like voltage, temperature or speed (e.g. a speedometer); Digital computers process discrete binary data — 0s and 1s (e.g. a desktop PC or smartphone); and Hybrid computers combine both — for example, an ICU machine that reads analog vital signs but displays a digital readout.

Answer: The motherboard is the main printed circuit board inside the computer cabinet. It physically connects and allows communication between the CPU, RAM, storage devices, expansion cards (graphics, sound, network) and all ports, acting as the central nervous system of the computer.

Answer: Input devices feed data and instructions into the computer. Common examples: Keyboard — typing text/commands; Mouse/Trackball/Glide‑pad — pointing and clicking; Joystick/game devices — controlling movement in games; Light Pen — drawing/selecting directly on screen; Touch Screen — direct finger/stylus input (ATMs, smartphones); Digitizer/Graphic Tablet — converts hand‑drawn art to digital form; Mic — voice input; Camera — photo/video input; POS Terminal & Scanners — reading price/product data at checkout; MIDI Keyboard — musical input; Wireless devices — Bluetooth/RF keyboards and mice that remove the cable.

Answer: A magnetic disk surface is divided into concentric circular rings called tracks. Each track is further divided into pie‑shaped sections called sectors, which are the smallest unit the disk reads/writes in a single operation. The operating system groups a number of sectors together into a cluster to manage storage more efficiently. When a disk drive has several stacked platters, the same track number on every platter, taken together, is called a cylinder — data in one cylinder can be accessed without moving the read/write arm, which is faster. Retrieving data involves seek time (moving the head to the right track) plus rotational delay (waiting for the right sector to spin under the head), and together these make up the access time.

Answer: OCR (Optical Character Recognition) converts printed or handwritten text images into editable digital text. OMR (Optical Mark Recognition) detects filled‑in marks on a sheet, used for checking OMR answer sheets. MICR (Magnetic Ink Character Recognition) reads special magnetic ink characters, mainly used on bank cheques. OBR (Optical Bar Recognition) reads barcodes printed on retail products at a checkout counter.

Answer: Seek Time is the time the read/write head takes to move to the correct track. Rotational Delay (latency) is the time the disk takes to spin so that the required sector comes under the head. Access Time is the sum of seek time and rotational delay — the total time to locate the data. Response Time is the total time from the moment data is requested until the first byte is actually delivered to the user.

Answer: Impact printers print by physically striking an inked ribbon against the paper, similar to a typewriter — they are noisy, relatively cheap, and can print carbon copies in one pass; examples include the Dot Matrix Printer and the Daisy Wheel Printer. Non‑Impact printers transfer ink or toner onto paper without any physical striking action — they are quieter and produce higher‑quality output, but usually cannot make carbon copies; examples include the Inkjet Printer and the Laser Printer.

Answer: LCD (Liquid Crystal Display) is a flat panel that uses liquid crystals to control light, making it thin and energy‑efficient. LED (Light Emitting Diode) display is essentially an LCD panel that is backlit by LEDs instead of older fluorescent tubes, giving better brightness and contrast. Plasma Display uses tiny cells of electrically charged gas to produce light, and is typically used in large‑screen televisions.

Answer: A plotter is an output device that draws precise, continuous line‑based graphics using pens or ink jets, rather than building an image from dots like a printer. It is commonly used to produce engineering drawings, architectural blueprints, and maps that require high positional accuracy.

Answer: To Binary (divide by 2): 35÷2=17 r1, 17÷2=8 r1, 8÷2=4 r0, 4÷2=2 r0, 2÷2=1 r0, 1÷2=0 r1 → reading remainders bottom‑to‑top gives 100011₂. To Octal (divide by 8): 35÷8=4 r3, 4÷8=0 r4 → 43₈. To Hexadecimal (divide by 16): 35÷16=2 r3, 2÷16=0 r2 → 23₁₆. (Check: 100011₂ grouped in 3s = 100 011 = 4,3 → 43₈ ✓, matching the octal answer.)

Answer: To subtract using 1's complement: flip every bit of the number being subtracted (0→1, 1→0), add it to the first number, and if there is a leading carry, add that carry back into the result (end‑around carry). Example: 1010 − 0011 → 1's complement of 0011 is 1100 → 1010+1100 = 1 0110 → add the carry back: 0110+1 = 0111 = 7 (since 10−3=7 ✓). To subtract using 2's complement: take the 1's complement and add 1 to it, then add to the first number and simply discard any leading carry (no end‑around addition needed). Example: 2's complement of 0011 = 1100+1 = 1101 → 1010+1101 = 1 0111 → discard the leading 1 → 0111 = 7 ✓. 2's complement is preferred in real computer circuits because it needs no extra correction step.

Answer: ASCII (American Standard Code for Information Interchange) is a 7/8‑bit code representing English letters, digits and symbols (e.g. 'A' = 65 = 01000001). BCD (Binary Coded Decimal) stores each decimal digit separately as its own 4‑bit binary group. EBCDIC (Extended Binary Coded Decimal Interchange Code) is an 8‑bit character code used mainly on IBM mainframes. Unicode uses 16 bits or more so it can represent characters from virtually every language in the world, unlike ASCII which only covers English.

Answer: A parity bit is an extra bit added to a byte to detect transmission errors. In even parity, the parity bit is chosen so the total count of 1‑bits (data bits + parity bit) is even; in odd parity, it is chosen so the total count is odd. Example: for data 1010001 (three 1‑bits), an even‑parity bit of 1 makes the total four 1‑bits (even), while an odd‑parity bit of 0 keeps the total at three 1‑bits (odd).

Answer: A Bit is a single binary digit (0 or 1), the smallest unit of data. A Nibble is a group of 4 bits. A Byte is a group of 8 bits and typically represents one character. A Carry Bit is generated when adding two bits produces a result exceeding the maximum single‑digit value, so it is carried to the next column. A Sign Bit is the leftmost bit of a binary number used to indicate whether the number is positive (0) or negative (1).

Answer: A Compiler translates the entire high‑level source program into machine code in one pass before execution begins; the resulting program then runs directly and fast, but any error is only reported after the whole program is scanned, and the compiled file is specific to one machine/OS. An Interpreter translates and executes the program line‑by‑line, without producing a separate machine‑code file; it starts running immediately and reports errors as soon as they are hit, but is generally slower overall since translation happens every time the program runs. C uses a compiler, while languages like Python (and classic BASIC) traditionally use an interpreter.

Answer: A Batch Operating System groups similar jobs together and processes them as a batch with no user interaction during execution — e.g. old payroll‑processing systems. A Multi Processing Operating System uses two or more CPUs within one system so that several processes truly run at the same time. A Time Sharing Operating System divides CPU time into small slices distributed among multiple users so quickly that each user feels they have the computer's full attention. An Online and Real Time Operating System processes data the instant it arrives and guarantees a response within a strict time limit — essential in systems like flight control or airbag sensors, where a late response is a failure.

Answer: 3GL (Third Generation Language) languages are procedural, English‑like high‑level languages such as C and Pascal. 4GL (Fourth Generation Language) languages are closer to natural language and focus on "what" rather than "how", such as SQL. 5GL (Fifth Generation Language) languages are problem‑solving and AI‑oriented, such as Prolog, where the programmer states constraints/goals and the system works out the steps.

Answer: Cloud Computing is the delivery of computing services — servers, storage, databases and software — over the internet, so an organisation can use computing resources on demand instead of owning and maintaining physical hardware. Its three service models are layered like a pyramid: IaaS (Infrastructure as a Service) rents raw computing infrastructure such as virtual servers and storage, and the customer manages everything above that — e.g. AWS EC2, Google Compute Engine. PaaS (Platform as a Service) additionally provides the runtime platform and development tools so the customer only manages their application code — e.g. Google App Engine, Azure App Service. SaaS (Software as a Service) delivers a complete, ready‑to‑use application over the internet, and the customer simply uses it with nothing to install or manage — e.g. Gmail, Netflix, MS 365.

Answer: A computer virus is a malicious, self‑replicating program that attaches itself to a host file or program and spreads from one computer to another, often corrupting or destroying data. Common types: Boot Sector Virus infects the master boot record and activates at system start‑up; File Infector Virus attaches to executable files and spreads when the file is run; Macro Virus hides inside document macros (e.g. Word/Excel); Worm self‑replicates and spreads across a network without needing a host file or user action; Trojan Horse disguises itself as legitimate software while carrying hidden malicious code; Ransomware encrypts the victim's data and demands payment for the decryption key. Preventive measures include installing and regularly updating trusted antivirus software, avoiding downloads/attachments from unknown sources, keeping the OS and applications patched, taking regular data backups, and using a firewall while scanning external drives before opening them.

Answer: Both GSM and CDMA are mobile communication standards. GSM (Global System for Mobile communication) uses a removable SIM card and divides each radio channel into time slots shared among users (time‑division access). CDMA (Code Division Multiple Access) does not typically use a removable SIM in the same way and instead gives every user a unique code so multiple users can share the same frequency simultaneously (code/spread‑spectrum access).

Answer: Bluetooth is a short‑range (a few metres), low‑power wireless technology mainly used for direct device‑to‑device connections, such as connecting a phone to earphones. Wi‑Fi has a much longer range, offers higher data speed, and is used to connect multiple devices to a shared network (like a router), typically for internet access.