Test: Input & Output Devices- 1 - Class 9 MCQ

Input Devices:
- Keyboard and mouse are considered as input devices.
- These devices allow users to input data and commands into a computer system.
Output Devices:
- Output devices are used to display or present data from a computer system.
- Examples of output devices include monitors, printers, and speakers.
Comparison:
- Keyboard and mouse are input devices, not output devices.
- They are used to input data and commands, rather than displaying or presenting data.
- Therefore, the correct answer is option A:

Input Devices

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Types of Monitors: CRT and LCD
Introduction:
CRT and LCD are two basic types of monitors used in various electronic devices. They are responsible for displaying visual information and graphics.
CRT (Cathode Ray Tube) Monitor:
- CRT monitors use a cathode ray tube technology.
- They have a bulky and deep design with a curved screen.
- The image is formed by shooting a beam of electrons onto a phosphor-coated screen.
- Advantages of CRT monitors include better color accuracy and contrast ratio.
LCD (Liquid Crystal Display) Monitor:
- LCD monitors use liquid crystal technology.
- They have a flat and thin design with a flat screen.
- The image is formed by manipulating light through liquid crystal cells.
- LCD monitors are more energy-efficient and offer a sharper image.
Differences between CRT and LCD monitors:
- Size and Weight: CRT monitors are bulkier and heavier compared to LCD monitors.
- Image Quality: CRT monitors generally offer better color accuracy and contrast ratio, while LCD monitors provide sharper images.
- Energy Efficiency: LCD monitors consume less power than CRT monitors.
- Lifespan: CRT monitors have a longer lifespan compared to LCD monitors.
- Space Efficiency: LCD monitors take up less space on a desk due to their slim design.
Conclusion:
In summary, CRT and LCD are two basic types of monitors used in electronic devices. CRT monitors use cathode ray tube technology and provide better color accuracy, while LCD monitors use liquid crystal technology and offer a sharper image. The choice between CRT and LCD depends on factors such as size, weight, image quality, energy efficiency, lifespan, and space efficiency.

The mouse is a primary input device but lacks the ability to easily transmit textual information.

When discussing the limitations of a mouse as a primary input device, it is important to note that it primarily focuses on graphical input and interaction. While a mouse allows users to interact with graphical elements on a computer screen, it lacks the ability to easily transmit textual information. Here's why:

• Graphical Input: A mouse excels at capturing graphical input, allowing users to click, drag, and interact with objects on the screen. It provides precise control over cursor movement and enables users to navigate through graphical interfaces.


• Limited Textual Input: However, when it comes to entering textual information, a mouse is not the most efficient tool. It is designed for pointing and clicking, making it challenging to input large amounts of text quickly and accurately.


• Text Entry Methods: While a mouse can be used for basic text input, such as clicking on virtual keyboards or selecting individual letters, it is not designed for extensive typing. This limitation becomes apparent when dealing with tasks that require a significant amount of textual input, such as writing documents or coding.


• Alternative Input Devices: To overcome the limitations of a mouse for textual input, alternative input devices such as keyboards are commonly used. Keyboards provide a more efficient and convenient way to enter textual information, allowing users to type quickly and accurately.

In conclusion, while a mouse is a primary input device and excels at graphical input, it lacks the ability to easily transmit textual information. For tasks that involve extensive text input, alternative input devices like keyboards are more suitable and efficient.

Plotters can be generally divided into ______ categories, namely ______.
The correct answer is option A: Two, Pen Plotters, and Electrostatic Plotters.
Explanation:
Plotters are output devices used to create high-quality, large-scale graphics. They work by drawing continuous lines on paper or other materials based on digital instructions. Plotters can be divided into different categories based on their technology and design. In this particular question, there are two main categories of plotters mentioned: Pen Plotters and Electrostatic Plotters.
Pen Plotters:
- Pen plotters use a pen or marker to draw lines on paper.
- They have a movable pen holder that can hold different colored pens or markers to create colorful and detailed drawings.
- Pen plotters are known for their precision and ability to create intricate designs.
Electrostatic Plotters:
- Electrostatic plotters use a process called electrostatic printing to create images.
- They use an electrostatic charge to attract and deposit toner particles onto a surface, typically paper or film.
- Electrostatic plotters are commonly used for printing architectural and engineering drawings.
It is important to note that while the question mentions "Plotters and Electrostatic," electrostatic plotters fall under the category of electrostatic plotters.
In summary, plotters can be generally divided into two main categories: Pen Plotters and Electrostatic Plotters.

Printer resolution is usually in Dots per Inch.
- Printer resolution refers to the level of detail that a printer can produce in its output.
- It is measured in Dots per Inch (DPI), which indicates the number of ink dots that can be printed in a linear inch.
- The higher the DPI, the more detailed and crisp the printout will be.
- Printer resolution is an important factor to consider when choosing a printer, especially for tasks that require high-quality prints such as graphic design or photography.
- DPI is not the only factor that affects print quality; factors like ink type, paper quality, and printing technology also play a role.
- In addition to DPI, printers may also specify resolution in other units such as PPI (Pixels per Inch) for digital printing or LPI (Lines per Inch) for halftone printing.
- DPI is commonly used because it represents the physical dots that can be printed, while PPI refers to the number of pixels in a digital image and LPI refers to the density of lines in a halftone image.
- It is important to note that DPI is different from print size. DPI determines the level of detail, while print size is the physical dimensions of the printout.
- To achieve high-quality prints, it is recommended to use images and documents with a resolution that matches or exceeds the printer's DPI.

Explanation:
The arrangement of keys on a QWERTY keyboard layout is not based on the phonetics of the alphabet, the frequency of usage, or the proximity of letters for convenient typing. Instead, it is based on the historical design of typewriters. Here is a detailed explanation:
1. QWERTY keyboard layout:
- The QWERTY keyboard layout is the most commonly used keyboard layout for English-language keyboards.
- It gets its name from the first six letters in the top row of keys: Q, W, E, R, T, and Y.
2. Historical design:
- The QWERTY layout was designed in the 1860s by Christopher Latham Sholes for the typewriter.
- The goal of the layout was to prevent mechanical jams in early typewriters by placing commonly used letters apart from each other.
- The layout was optimized for the mechanical operation of typewriters, not for efficient typing or phonetic representation.
3. Efficiency concerns:
- The QWERTY layout is not the most efficient layout for typing.
- Alternative layouts, such as the Dvorak Simplified Keyboard or Colemak, have been designed to increase typing speed and reduce finger movement.
- These alternative layouts rearrange the keys based on factors like finger strength, frequency of letter usage, and hand movement patterns.
4. Persistence of QWERTY:
- Despite the availability of more efficient layouts, the QWERTY layout remains dominant.
- The widespread adoption of QWERTY keyboards, familiarity, and resistance to change have contributed to its persistence.
In conclusion, the arrangement of keys on a QWERTY keyboard layout (Q, W, E, R, T, Y) is based on the historical design of typewriters rather than factors like phonetics, frequency of usage, or convenient typing.

Toggle Key
- The correct answer is Toggle key.
- A toggle key is a key on a computer keyboard that turns a specific feature on or off.
- The most common example of a toggle key is the Caps Lock key, which toggles the capitalization of letters.
- Toggle keys are designed to provide a convenient way to enable or disable certain functions without the need for complex key combinations.
- These keys are labeled with specific symbols or words that indicate their function.
- Toggle keys can be found on various keyboards, including desktop keyboards, laptop keyboards, and even on-screen keyboards.
- Some common examples of toggle keys include Caps Lock, Num Lock, and Scroll Lock.
- While Caps Lock toggles the capitalization of letters, Num Lock toggles the functionality of the numeric keypad, and Scroll Lock toggles the scrolling behavior of the keyboard.
- Toggle keys are useful for quickly switching between different modes or settings, providing a more efficient and user-friendly computing experience.

The pointing device that can be used to control the pointer by rotating a ball with your thumb is a trackball.
Here is a detailed explanation of why the answer is trackball:
Trackball:
- A trackball is a pointing device that consists of a ball mounted on a socket that can be rotated with the thumb or fingers.
- It is designed to provide precise cursor control and is often used as an alternative to a mouse.
- The ball can be rolled in any direction to move the cursor on the screen, allowing for easy navigation and control.
- Trackballs are commonly used in situations where space is limited or for individuals with mobility issues who find it difficult to use a traditional mouse.
- They are often found in laptops, gaming devices, and specialized input devices.
Other Options:
- Pointing stick: A pointing stick is a small joystick-like device found on some laptops that can be used to control the cursor. However, it is not rotated like a ball with the thumb.
- Touchpad: A touchpad is a flat surface found on laptops that can be used to control the cursor by moving your finger across it. It does not involve rotating a ball.
- Joystick: A joystick is a device used primarily for gaming that consists of a stick that can be moved in different directions to control the cursor or characters in a game. It does not involve rotating a ball.
Therefore, the correct answer is D: Trackball.

The correct answer is D: Character and mark recognition device. This is not a type of scanning device.
Explanation:
Here is a detailed explanation of the different types of scanning devices mentioned in the options:
1. Optical scanner: This scanning device uses light to capture images or text and convert them into digital data. It can be used to scan documents, photos, or any printed material.
2. Bar code reader: This scanning device is specifically designed to read barcodes. It uses laser beams or image sensors to capture the barcode information, which is then converted into readable data.
3. Light pen: This is a handheld input device that allows the user to directly interact with the computer screen by pointing at it. It uses light-sensitive technology to detect the position of the pen on the screen.
4. Character and mark recognition device: This is not a type of scanning device. It refers to software or systems that can recognize and interpret handwritten characters or marks on a document. It does not involve physical scanning, but rather the processing of scanned images or digital documents.
In conclusion, the correct answer is D: Character and mark recognition device, as it is not a type of scanning device.

The correct answer is A: MICR.
MICR, which stands for Magnetic Ink Character Recognition, is the reading device used in banks to read the numbers on the bottom of checks and deposit slips.
Here is a detailed explanation of the different options and why MICR is the correct answer:
A: MICR (Magnetic Ink Character Recognition)
- MICR is a technology used by banks to process checks and deposit slips.
- It involves printing numbers and characters on the bottom of checks and deposit slips using magnetic ink.
- The MICR reading device uses magnetic sensors to read these numbers and characters, which are then processed by the bank's systems.
- MICR is widely used in the banking industry for its accuracy and efficiency in check processing.
B: OCR (Optical Character Recognition)
- OCR is a technology that converts printed or handwritten text into machine-readable data.
- While OCR can be used to read numbers and characters, it is not specifically designed for reading the numbers on the bottom of checks and deposit slips.
- OCR is commonly used for tasks such as scanning documents, recognizing text in images, and extracting data from printed forms.
C: OMR (Optical Mark Recognition)
- OMR is a technology used to detect and recognize marks on paper forms, such as checkboxes or bubbles filled in with a pen or pencil.
- OMR is not used for reading the numbers on the bottom of checks and deposit slips.
- OMR is commonly used in applications such as surveys, questionnaires, and multiple-choice answer sheets.
D: UPC (Universal Product Code)
- UPC is a barcode symbology widely used for product identification and inventory management in retail.
- UPC codes are not used for reading the numbers on the bottom of checks and deposit slips.
- UPC codes consist of a series of vertical bars and spaces that represent numbers and are typically scanned by barcode readers.
In conclusion, the correct answer is A: MICR, as it is the specific technology used in banks to read the numbers on the bottom of checks and deposit slips.