Computer Hardware : MCQs & PYQs with Explanation

Option D

An input device is a hardware device used to provide data and control signals to a computer. It allows users to enter information into the computer system for processing.

Input Devices and Their Functions:

Output Devices and Their Functions:

Devices with Both Input and Output Functions:

Option B

An input device is a hardware device used to provide data and control signals to a computer. It allows users to enter information into the computer system for processing.

Input Devices and Their Functions:

Output Devices and Their Functions:

Devices with Both Input and Output Functions:

Option C

Dot Matrix Printers are Impact Printers that use tiny pins to strike an ink ribbon, forming characters or images as a pattern of dots on paper.
They are called Serial Printers because they print one character at a time, moving horizontally across the page.
In contrast, line printers print one entire line at a time, and page printers (laser printers) print a full page at once.

Option B

A Joystick is an input device used to control the movement or actions of a device or object in a graphical environment or machine. It typically consists of a stick that can move in multiple directions, often accompanied by buttons for performing additional actions.

Joysticks are commonly employed in situations where precise, real-time control of movement is required, such as operating industrial robots, playing computer games, or training with flight simulators.

Option A

The Keyboard is the primary text input device of a computer, enabling users to enter alphanumeric and special characters directly.

Option D

Sensors are specialized input devices that measure physical conditions such as, temperature, humidity / moisture, pressure, and light intensity. The sensor convert these measurements into electrical signals that a computer can process.

Option A

A QR Code (Quick Response Code) has three position-detection squares that help scanners identify the orientation of the code.

• Two squares are located at the top-left and top-right corners.
• The third square is located at the bottom-left corner.

These position markers allow QR readers to quickly detect, align, and decode the information, regardless of the code’s angle or rotation.

Option C

Hardware refers to the physical components of a computer system, the parts that you can see and touch, such as the keyboard, monitor, printer, and motherboard. Hardware performs tasks based on the instructions given by software.

Software refers to the set of programs or instructions that tell the hardware how to perform specific tasks. It cannot be touched physically and includes applications like MS Word, Web Browser (Chrome, Firefox, Edge), and the operating system.

Option C

A Pointing Device is input device that allows a user to interact with a computer by controlling the movement of a pointer on the screen.

Option C

Option D

A CD audio player reads sound data stored on a compact disc using a laser beam. The CD surface contains tiny pits and lands that represent digital audio information. When the laser beam falls on the disc, it detects these pits and lands and converts the reflected light into electrical signals, which are then processed to reproduce sound.

Option A

SD (Secure Digital, launch in the year 1999 by Panasonic, Toshiba, SanDisk), a type of non-volatile memory card used in cameras, mobiles, laptops, etc. The term "Secure Digital" refers to the original purpose, providing secure, portable storage for digital devices.

MMC (Multimedia Card, launch in the year 1997 by Siemens & SanDisk), an older memory card standard developed before SD cards. These are similar in size, but slower and less secure compared to SD.

• SD stands for Secure Digital, which is modern, secure, and widely used in devices like cameras, smartphones, and laptops. On the other hand, MMC stands for Multimedia Card, which is an older standard with limited speed and storage, and is now mostly replaced by SD cards.

Option B

Printers are output devices that produce hard copies of digital documents. Common printer types are:

• Inkjet Printer (Non-Impact Printers) : Sprays tiny droplets of liquid ink directly onto paper. Widely used for home and office printing.
• Dot-Matrix Printer (Impact Printers) : Uses pins to strike an ink ribbon and form characters.
• Laser Printer (Non-Impact Printers) : Uses laser beam and toner powder to print high-quality text or images, popular in offices.
• 3D Printer (Non-Impact Printers) : A printer type that creates three-dimensional objects by laying down material layer by layer, used in prototyping and manufacturing.
   

Option C

LCD (Liquid Crystal Display) panels work on the principle of light modulation. The main job of an LCD is to "modulate" light, not generate it.

Instead of producing light by themselves, LCDs use a backlight behind the panel. The liquid crystals in the display control how much light passes through to create the images you see. To do this, the crystals change their orientation when electricity is applied, allowing more or less light to pass through each part of the display.

Common Display Technologies:

Option C

A computer system communicates with the outside world through input and output devices. 
Input Devices are used to send data and instructions to the computer, allowing users to interact with and control the system. Examples of input devices include the keyboard, mouse, scanner, and microphone. 

Output Devices receive information from the computer and present it in a form understandable to the user. Common examples of output devices are monitors, printers, and speakers.