Input/Output — Set 3
Computers · इनपुट/आउटपुट · Questions 21–30 of 70
The 'Caps Lock' and 'Num Lock' keys on a keyboard are known as?
Correct Answer: A. Toggle Keys
Toggle keys are keys that switch a specific feature on or off each time they are pressed. For example, Caps Lock switches between uppercase and lowercase letters. An indicator light usually shows whether the toggle is currently active.
Which output device is used to show computer images to a large audience on a wall or screen?
Correct Answer: C. Multimedia Projector
A projector takes the image signal from a computer and uses a bright light source to enlarge it onto a distant surface. It is widely used in classrooms and corporate boardrooms for presentations. Modern projectors can display high-definition video.
Which input device uses a pressure-sensitive surface and a pen-like tool for digital art?
Correct Answer: D. Graphics Tablet
A graphics tablet, also known as a digitizer, allows artists to draw by hand as if they were using a real pen on paper. The device captures the pressure and tilt of the stylus to create detailed digital strokes. It is an essential tool for professional digital illustrators.
What is the function of the 'Print Screen' key on a keyboard?
Correct Answer: A. To capture an image of the current screen
The Print Screen key captures a snapshot of the entire desktop and copies it to the clipboard. This image can then be pasted into a document or image editor. In modern operating systems, it is often used in combination with other keys for more options.
Which technology is used in 'Touchscreen' devices to detect a finger touch?
Correct Answer: C. Capacitive or Resistive
Capacitive touchscreens use the electrical properties of the human body to detect a touch, while resistive screens respond to physical pressure. Capacitive screens are standard on modern smartphones because they support multi-touch gestures. This eliminates the need for external pointing devices.
The speed of a computer printer is usually measured in which unit?
Correct Answer: D. PPM
PPM stands for Pages Per Minute, indicating how many full sheets a printer can produce in sixty seconds. High-speed commercial printers can exceed 50 PPM. DPI (Dots Per Inch), on the other hand, measures the print quality or resolution.
Which input device is used for playing high-end flight simulators and arcade games?
Correct Answer: A. Joystick
A joystick allows for multi-directional control, making it perfect for simulating aircraft movements. It often includes several buttons and a trigger for specific in-game actions. It is one of the oldest peripheral devices used for computer interaction.
What is the purpose of 'OCR' (Optical Character Recognition) software?
Correct Answer: C. To convert scanned text images into editable text
OCR technology scans a digital image of text and identifies the individual letters and words. This allows a computer to treat a picture of a document as a searchable and editable text file. It is widely used for digitizing old books and receipts.
Which output device provides audio feedback primarily for a single user without disturbing others?
Correct Answer: D. Headphones
Headphones are small speakers designed to be worn on or around a user's ears. They provide a private listening experience and are often used with computers for music or gaming. Wireless versions use Bluetooth technology to connect to the system.
Which device is both an input and an output device?
Correct Answer: A. Touch Screen
A touch screen acts as an output device by displaying images and as an input device by detecting user touches. This dual functionality is common in tablets, smartphones, and ATMs. It creates a direct interaction between the user and the graphical interface.