Computer Science

OCR stands for Optical Character Recognition, which is the technology used to convert different types of documents, such as scanned paper documents or images, into editable and searchable data.

A light pen is an input optical device that allows users to point to displayed objects on a screen by detecting light from the screen.

A headphone is an output device because it outputs sound from the computer to the user. It does not take input from the user, so it is not an input or input/output device.

A daisy wheel printer uses a rotating wheel with characters on the petals (like a daisy) to strike an ink ribbon and print characters. This mechanical impact method is characteristic of daisy wheel printers, distinguishing them from non-impact printers and those that print graphics or color.

A joystick functions similarly to a mouse as both are pointing input devices used to control the movement of a cursor or pointer on a screen. Unlike keyboards, cameras, or monitors, joysticks provide directional input akin to a mouse.

MICR (Magnetic Ink Character Recognition) is the technology used by banks to read data on cheques because it allows for fast and accurate reading of the special magnetic ink characters printed on cheques. OCR and OMR are used for different purposes, and bar-code readers are not typically used for cheque processing.

A barcode reader is an input device because it scans and inputs data (barcode information) into a computer system for processing.

A printer is an output device because it produces a physical copy of digital documents, whereas a keyboard and scanner are input devices. Therefore, the correct answer is Printer.

The 'Print Screen' key on a keyboard is specifically used to capture the current screen display, making option D the correct answer.

Speakers are output devices because they convert electrical signals into sound, allowing users to hear audio from the computer. They do not take input from users, so they are not input devices.