Basic components of a computer system

Correct answer: A. Monitor

Explanation: The governing concept is the difference between the system unit and external peripherals. In a typical desktop, the monitor is a separate external output device placed outside the system unit. The CPU chip, RAM module, and motherboard are internal components installed inside the system unit. Although the CPU can mean the processor or the whole system in casual speech, here option A is the unambiguous answer.

Correct answer: B. They are integrated into one portable unit

Explanation: The governing concept is the integrated design of a laptop. Its keyboard and screen are built into the same compact, portable computer body, allowing the user to carry and operate them together. They are not in separate rooms, are not necessarily wireless, and are not storage devices. Therefore, option B accurately describes their common feature.

Correct answer: C. Touchscreen

Explanation: The governing concept is input and output functionality. A touchscreen detects the user’s touch as input and also displays text, images, and controls as output, so it is a combined input-output component. A speaker produces sound, a battery supplies power, and a camera flash provides light; none accepts touch commands. Thus, option C is correct.

Correct answer: D. Ports and cables

Explanation: The governing concept is connectivity between hardware components. Ports provide connection points, while cables carry electrical or data signals between a computer and devices such as a monitor, keyboard, or storage drive. A folder organizes files, a file stores information, and software supplies instructions; none is the physical connection method. Hence, option D is correct.

Correct answer: A. Input provides data, the processor processes it, and output shows the result

Explanation: The governing concept is the input-process-output cycle. Input devices provide data, the processor applies instructions to that data, and output devices present the resulting information. Storage may retain data and software provides instructions, but neither definition matches the distractors. A correctly describes the normal flow, whereas B reverses functions and C and D give false single-purpose claims.

Correct answer: B. Hardware, software, data and user

Explanation: The governing concept is that a computer system works through the interaction of hardware, software, data, and users. Hardware provides the physical equipment, software supplies instructions, data is processed, and the user operates or directs the system. Therefore, option B is complete. Options A and C list only a few devices, while internet and cables alone cannot form a complete computer system.

Correct answer: A. Bus

Explanation: In computer architecture, a bus is a set of electrical pathways and communication lines that carries data, addresses, and control signals between components such as the processor, memory, and input/output devices. Thus, option A is correct. A folder organizes files, a cursor indicates a position on the screen, and a shortcut provides quick access; none is a motherboard data pathway.

Correct answer: C. Input devices

Explanation: The governing concept is the direction of information flow. Input devices send data, instructions, or signals into a computer; keyboards, mice, scanners, and microphones are common examples. Therefore, option C is correct. Storage devices retain information, output devices present processed results, and communication devices mainly exchange information between systems, so they do not define data entry into the computer.

Correct answer: A. Keyboard

Explanation: A keyboard is an input device designed to enter letters, numbers, punctuation marks, and special symbols by pressing keys. Therefore, option A is correct. A scanner captures printed material as digital input, but it is not normally used to type characters; a speaker produces sound and a projector displays images. The task described specifically requires keyboard input.

Correct answer: B. Mouse

Explanation: A mouse is a pointing input device. Moving the mouse moves the pointer, and its buttons allow the user to select, open, drag, or activate items on the screen. Thus, option B is correct. A monitor only displays visual output, a printer creates paper output, and a speaker produces sound; none directly controls the on-screen pointer.

Correct answer: D. Printer

Explanation: A printer is an output device that transfers text, images, or other processed information from a computer onto paper. The printed result is called a hard copy, so option D is correct. A scanner performs the reverse direction by sending paper content into the computer, while a mouse and microphone provide user input rather than paper output.

Correct answer: C. Arithmetic Logic Unit

Explanation: The Arithmetic Logic Unit, or ALU, is the CPU section responsible for arithmetic operations such as addition and subtraction and logical operations such as comparing two values. Therefore, option C is correct. The Control Unit directs instruction execution, memory stores information, and the Power Supply Unit provides electrical energy; none performs the central calculations and comparisons.

Correct answer: D. Control Unit

Explanation: The Control Unit is the CPU component that fetches and interprets instructions and coordinates their execution by directing other parts of the computer. Thus, option D is correct. A monitor presents visual output, a speaker produces audio, and a hard disk stores data. Those components support the system but do not manage the sequence and coordination of operations.

Correct answer: A. Random Access Memory

Explanation: Random Access Memory, or RAM, is the computer’s temporary working memory. It holds currently running programs and the data they need so the processor can access them quickly. Therefore, option A is correct. RAM is volatile, so its contents normally disappear when power is removed; ROM, compact discs, and hard disks are non-volatile storage forms.

Correct answer: B. Read Only Memory

Explanation: The governing concept is the difference between volatile and non-volatile memory. Read Only Memory (ROM) is non-volatile primary memory, so it retains essential instructions such as boot instructions when power is removed. Therefore, option B is correct. RAM and cache are generally volatile working memories, while a hard disk is secondary storage rather than primary memory.

Correct answer: C. Hard Disk

Explanation: The governing concept is long-term or secondary storage. A hard disk stores files, applications, and other data magnetically and keeps them available even after the computer is switched off. Therefore, option C is correct. RAM is volatile working memory and normally loses its contents when power is removed, while a mouse and microphone are input devices, not storage components.

Correct answer: D. Solid State Drive

Explanation: The governing concept is the construction of storage devices. A Solid State Drive (SSD) stores data in flash memory chips and has no spinning platters, motor, or read/write head. This allows fast access and makes option D correct. Floppy disks, compact discs, and magnetic tape depend on mechanical movement or rotating media, so they are not the best answer to this description.

Correct answer: A. Scanner

Explanation: The governing concept is input and output in a computer system. A scanner optically reads text or images from a paper document and converts them into digital data that a computer can store or edit. Therefore, option A is correct. A printer produces paper output, while a speaker and monitor present sound or visual output rather than capturing a paper document as input.

Correct answer: B. Microphone

Explanation: The governing concept is the direction of data flow. A microphone captures sound waves and converts them into electrical or digital signals that the computer can record, process, or save. Thus, option B is correct. A speaker sends sound outward as an output device, a monitor displays visuals, and a webcam mainly captures video, although some webcams may also include a microphone.

Correct answer: C. Webcam

Explanation: The governing concept is video input. A webcam uses a camera sensor to capture a person or scene and sends the resulting video data to the computer or mobile device for transmission during a call. Therefore, option C is correct. A keyboard provides typed input, a speaker produces audio output, and a printer creates paper output; none captures live video.

Correct answer: A. Projector

Explanation: The governing concept is visual output. A projector receives image or video signals from a computer and enlarges the content onto a wall or projection screen, making it useful for classrooms and presentations. Therefore, option A is correct. A microphone captures sound, a keyboard enters text, and a scanner captures paper documents; these devices do not display computer content on a large surface.

Correct answer: B. Touchscreen

Explanation: The governing concept is a device that combines input and output functions. A touchscreen displays images, text, and controls while also detecting the user’s finger or stylus touches as commands. Therefore, option B is correct. A speaker gives audio output, a printer produces paper output, and a scanner primarily captures documents as input; none normally provides both functions through the same surface.

Correct answer: C. Motherboard

Explanation: The governing concept is the organization of computer hardware. The motherboard is the main printed circuit board that provides connections and communication pathways for the processor, memory, storage interfaces, expansion cards, and other components. Therefore, option C is correct. A hard disk stores data, a power supply provides electrical power, and a monitor displays output; none is the computer’s main circuit board.

Correct answer: D. Power Supply Unit

Explanation: The governing concept is the role of the power supply in computer hardware. The Power Supply Unit (PSU) receives electrical power from an outlet and converts it into suitable regulated voltages for the motherboard, processor, drives, fans, and other internal parts. Therefore, option D is correct. A webcam, mouse, and scanner are peripheral input devices and do not distribute power to the internal system.

Correct answer: A. Cooling fan

Explanation: The governing concept is computer cooling. A cooling fan circulates air through the case and helps carry heat away from components such as the CPU, thereby reducing the risk of overheating. A printer produces hard copies, while a keyboard and microphone provide input; none of these normally cools the inside of the computer. Therefore, option A is correct.