Question

what is odd man out of keyboard , microphone, headphone ,mouse

Answer 1

Headphone is the answer.
This is because it is an output device, and all others in the list are input devices.

Answer 2

The odd one out is headphones.

• While all others are input devices, headphones in common are output devices.
• These devices help the active user to listen to various kinds of audio.
• When headphones are linked to a standard computer, modern laptop, smartphone, or any other device, they typically receive necessary data from the machine.
• As a direct result, headphones are considered output devices.