Which of the following devices is not primarily used as an input device for sending data or commands into a computer system?

Introduction / Context:
Computer peripherals are often categorised as input devices, output devices or both. Input devices send data or control signals into the computer, while output devices present information to the user. This question asks you to identify which device in the list is not primarily used for input. Knowing the roles of common peripherals helps in understanding basic computer hardware and exam questions that test input versus output classification.

Given Data / Assumptions:

• The options list common devices: joystick, headphones, mouse, scanner and microphone.
• Input devices send signals into the computer for processing.
• Output devices receive processed information from the computer for the user.
• Some devices, like touch screens, can act as both, but the question focuses on primary use.

Concept / Approach:
A joystick is an input device used mainly for games and simulations; moving it sends control signals into the system. A mouse is a classic pointing input device, sending position and click information to the computer. A scanner takes images or text from paper and converts them into digital data as input. A microphone sends audio signals into the computer, so it is also an input device. Headphones, by contrast, receive audio output from the computer and convert it into sound for the user. They do not send data into the computer under normal use. Therefore, headphones are not primarily an input device and are correctly classified as an output device.

Step-by-Step Solution:

Verification / Alternative check:
Hardware classification tables in computer fundamentals books list keyboard, mouse, joystick, scanner and microphone as input devices. In the same tables, monitor, printer, speakers and headphones appear under output devices. Product descriptions for headphones emphasise listening to music, games or calls from the computer, not controlling the computer. Some headsets combine headphones with a microphone; in that case, the headphone part is output and the microphone part is input. Since the question specifically names headphones, not a headset, it clearly refers to an output only device, confirming that it is not an input device.

Why Other Options Are Wrong:

• Joystick: Used to control games or simulations; it sends movement and button data into the computer as input.
• Mouse: A pointing input device used to control the graphical user interface.
• Scanner: Captures text or images from paper and sends them into the computer as digital data.
• Microphone: Captures sound waves and converts them into audio signals sent into the computer.

Common Pitfalls:
Some learners may confuse headphones with headsets or think of any audio device as both input and output. It is important to separate the functions: headphones only output sound, while microphones only input sound. In multi function devices, you must consider each component separately. For exam questions, focus on the primary role described; if it simply says headphones, treat it as an output device and therefore not an input device.

Final Answer:
The device that is not primarily used as an input device is Headphones, which are an output device.