Which of the following devices are computer input devices only ? (A) DVD - R…
2024
Which of the following devices are computer input devices only ?
(A) DVD - R
(B) Joystick
(C) Plotter
(D) Touch Pad
(E) Microphone
Choose the correct answer from the options given below :
Answer: B. (B), (D) and (E) Only — Concept — direction of data flow decides the class. A peripheral is classified by the direction in which data travels between it and the processor. An input…
- A.
(A), (D) and (E) Only
- B.
(B), (D) and (E) Only
- C.
(A), (B) and (C) Only
- D.
(B), (C), (D) and (E) Only
Show answer & explanation
Correct answer: B
Concept — direction of data flow decides the class.
A peripheral is classified by the direction in which data travels between it and the processor. An input device carries data one way only, from the user or the environment into the computer. An output device carries processed data one way only, from the computer out to the user. A storage medium is two-way: the drive writes data onto it and later reads that data back, so it sits in neither pure class. The qualifier “input devices only” therefore selects devices whose data flow is strictly inward.
Application — classify each of the five devices.
Device | Direction of data flow | Class |
|---|---|---|
DVD-R | A drive burns data onto the disc and later reads it back — both directions | Storage medium |
Joystick | Stick deflection and button states travel inward | Input device |
Plotter | Vector drawing data travels outward and is laid onto paper | Output device |
Touch Pad | Finger position and movement travel inward | Input device |
Microphone | Sound is converted to an electrical signal that travels inward | Input device |
Cross-check — the two rejected devices fail the test in opposite ways.
A DVD-R does hand data to the computer while it is being read, but the same drive also burns data onto it, so its flow is two-way rather than strictly inward — it is storage media, not an input device.
A plotter only receives drawing instructions and never returns drawing data to the computer, so its flow is strictly outward — it is a pure output device, the paper counterpart of a printer.
Result. Removing those two leaves three devices whose data flow is strictly inward — Joystick, Touch Pad and Microphone — which is the set “(B), (D) and (E) Only”.