General Science MCQ Practice

• Correct option: A — A CD-ROM is an optical disk that uses laser light to read data from a shiny, reflective surface on a polycarbonate disc.
• Key concept: Optical storage stores data with light, not magnetic fields.
• Why others are incorrect:
  • Magnetic disk (B) uses magnetic domains (e.g., hard drives).
  • Fibre disk (C) is not a standard storage type.
  • D None of these is false since A is correct.

• The correct answer is HTML because HTML (HyperText Markup Language) is used to structure content on web pages with tags and elements.
• Key concept: HTML defines the page layout and elements; HTTP/FTP are protocols for data transfer; URL is the web address.
• Small tip: Use HTML for content, CSS for styling, and JavaScript for interactivity.
• Why others are incorrect: HTTP is a protocol, FTP is a file-transfer protocol, and URL is a web address, not the language that structures the page.

• Why it's correct: Hardware comprises the tangible parts of a computer that you can see and touch (e.g., keyboard, monitor, motherboard).
• Key concept: Distinguish hardware (physical components) from software (programs and data).
• Brief note on others:
  • Software: intangible, cannot touch.
  • Liveware: not a standard term in computers.
  • Firmware: software stored in non-volatile memory; not typically visible to touch.
• Exam tip: If you can physically handle it, it’s hardware.

• Reason: A modem modulates digital computer signals to analog telephone lines and demodulates incoming analog signals back to digital form, enabling communication over telephone networks.
• Key concept: Data transmission over PSTN using modem modulation/demodulation.
• Tip: If options include “Network” or “Microprocessor,” remember a network connects devices; a modem specifically connects via telephone lines.
• Why other options are incorrect:
  • A. Microprocessor — handles internal computation, not communication over phone lines.
  • B. Network — describes a system of connected devices, not the device that enables dial-up communication.
  • C. Assembler — a programming translator, not a communication device.

• The parity bit helps detect single-bit errors by ensuring a constant number of 1s in a data unit.
• Key concept: parity check (even/odd parity) using XOR logic to detect discrepancies.
• Formula: total 1s in data + parity = even (or odd) as chosen.
• Why others wrong: Not for coding, controlling, or indexing data directly; it’s specifically for error detection.
• Exam tip: If a single bit flips, parity mismatch reveals an error; multiple bit errors may go undetected in simple parity.

• Correct option: A. Internet
• Reason: It is a network (global connectivity), not an operating system. Linux, Unix, and Windows are distinct operating systems.
• Key concept: Distinguish between an OS (software that manages hardware) and a network/internet (a system of connected computers).
• Tip: In MCQs, check if the term is an OS; if not, it’s often the odd one out.
• Why others are incorrect: Linux, Unix, and Windows are all operating systems; they perform hardware management and user interfaces.

• Why: Prolog is a logic programming language designed for artificial intelligence, enabling facts, rules, and query-based reasoning.
• Key concept: Uses predicates and backward chaining (goal-directed search) to infer answers from knowledge bases.
• Formula/numerical logic: Not math-heavy; relies on logical inference rather than arithmetic formulas.
• Why others are incorrect: FORTRAN and COBOL are traditional programming languages; INDEXING is not a language and has no AI focus.

Exam tip: Remember: AI languages emphasize knowledge representation and reasoning (e.g., Prolog) vs. general-purpose or business languages.