1. Optical fibres use total internal reflection to transfer data. The primary condition for total internal reflection is that the signal must travel from an optically denser medium to an optically rarer medium. Secondly, the angle of incidence must be greater than the critical angle.

An output device is a computer hardware device that displays or reproduces information processed by a computer in human-readable form. Output devices usually receive information from the computer through an input device, such as a mouse or keyboard.

Some examples of output devices include-

1. Monitor: A monitor is a visual output device that displays images generated by a computer.

2. Printer: A printer is a physical output device that prints computer-generated documents on paper.

3. Speaker: A speaker is an audio output device that reproduces the sound produced by the computer.

4. Headphone: A headphone is a personal audio output device that reproduces the sound generated by a computer solely for the user to hear.

5. Projector: A projector is similar to a monitor, but it projects images onto a larger screen.

6. GPS Device: A GPS device is an output device that displays its current location to the user on a map or other view.

7. Braille Reader: A Braille reader is an output device that displays computer-generated information in Braille for visually impaired people.