Device used to draw lines or figures on a computer screen:
There are several devices that can be used to draw lines or figures on a computer screen, but the most common device is a light pen. Here is a detailed explanation of the various devices and why a light pen is the correct answer:
1. Light pen:
- A light pen is a handheld input device that allows users to draw directly on a computer screen by pointing at it.
- It consists of a light-sensitive photocell that can detect light emitted by the screen.
- The light pen is connected to the computer and can transmit the coordinates of the drawing to the software.
- It is used in applications such as graphic design, digital art, and computer-aided design (CAD).
2. Joystick:
- A joystick is primarily used for controlling the movement of objects in video games or flight simulators.
- It does not have the precision or functionality to draw lines or figures on a computer screen.
3. Trackball:
- A trackball is a pointing device that consists of a ball housed in a socket with sensors to detect its movement.
- It is primarily used to move the cursor on the screen, but it does not have the capability to draw lines or figures.
4. Scanner:
- A scanner is a device used to convert physical documents or images into digital format.
- It captures the image or document and creates a digital representation of it.
- While it can be used to capture drawings or figures, it is not specifically designed for drawing directly on a computer screen.
Therefore, the correct answer is A: Light pen as it is specifically designed for drawing lines or figures on a computer screen.