In computer input and output devices, which one of the following is not considered an input device for entering data into a computer system?

Introduction / Context:
Computer peripherals are often classified as input or output devices depending on the direction in which information flows. Input devices send data into the computer for processing, while output devices present processed information to the user in visual, printed or audio form. This question asks you to identify which of the listed devices is not an input device. Being able to distinguish between input and output roles is a fundamental skill in computer fundamentals and general knowledge exams.

Given Data / Assumptions:

• The topic is input devices and one non input device among them.
• Options include a plotter, MICR, OMR, barcode reader and OCR device.
• MICR, OMR, barcode readers and OCR are commonly used for automated data entry.
• We assume standard definitions where input devices capture data and output devices display or print it.

Concept / Approach:
MICR, OMR, barcode readers and OCR devices all read information from physical media and convert it into digital form. MICR reads special ink characters on cheques, OMR detects marks on answer sheets, barcode readers scan barcodes on products and OCR systems convert printed text to machine readable text. All of these are clearly input devices. A plotter, on the other hand, is a type of output device used to produce high quality large format drawings and graphics on paper, particularly in engineering and architectural applications. It receives commands from the computer and draws lines or shapes on paper but does not send data into the computer. Therefore, the correct answer is plotter, which is not an input device.

Step-by-Step Solution:

Verification / Alternative check:
Introductory computer books classify plotters under output devices, along with printers and monitors. They describe plotters as devices that draw continuous lines and are used for large engineering drawings. In contrast, input devices are listed separately and include keyboard, mouse, MICR, OMR, barcode readers and OCR. Explanations emphasise that MICR and OMR are used to speed up data entry in banking and examinations, while barcode readers and OCR automate product scanning and text input. These consistent classifications confirm that plotter is not an input device but an output device, and thus the correct choice in the question.

Why Other Options Are Wrong:

• Magnetic Ink Character Recognition (MICR) device: Reads specially printed characters on documents such as cheques, so it is an input device.
• Optical Mark Recognition (OMR) device: Detects marks on answer sheets and forms, sending the data into the computer.
• Barcode reader (barcode scanner): Reads barcodes from products and transfers that information into the system.
• Optical character recognition (OCR) device: Converts printed or handwritten text into digital text, clearly acting as an input device.

Common Pitfalls:
Students sometimes confuse plotters with scanners because both involve paper and images. A good rule is to think about the direction of information flow: if the device takes data from the computer and draws or prints on paper, it is output; if it reads marks, characters or codes from paper and sends them into the computer, it is input. Remember that plotters and printers output images, while scanners, MICR, OMR and barcode readers input information. Using this rule makes it easy to recognise plotter as the non input device in this list.

Final Answer:
The device that is not an input device is the Plotter, which is an output device used for high quality drawings.