Computer question from Laboratory Attendant exam, 2026 by JKSSB
Which of the following statements about input and output devices is MOST accurate?
Last updated Jun 18, 2026
Correct Answer:
Option B —
Optical Character Recognition (OCR) scanners are purely input devices since they convert physical text into digital form, and cannot provide feedback or output to the user.
Explanation:
Why B is correct: An OCR scanner's sole hardware function is to capture physical optical data (light and dark patterns of text on a page) and feed it into a computer system as digital data. It acts exclusively as a unidirectional data pipeline into the system, making it a pure input device.
Why the other options are incorrect:
A is incorrect: A capacitive touchscreen is a hybrid input/output device. The physical glass layer contains sensors that detect electrical charges from a human finger at the hardware level; this translates directly to touch input.
C is incorrect: A standard digitizer tablet (like those used by graphic designers) is strictly an input device. It registers coordinates, pressure, and tilt from a stylus and sends that data to the computer. It does not output anything itself; the visual feedback happens on a completely separate device (the monitor).
D is incorrect: While Braille displays are indeed output devices, the statement's description is inaccurate. As established previously, they use mechanical raising and lowering of pins to create tactile characters, not haptic vibrations.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
