Question

Which of the following is not an input device ?
1. Mouse 
2. Light pen 
3. Keyboard 
4. VDU

Answer 1

Correct Answer - Option 4 : VDU

The correct answer is VDU.

• Visual Display Unit (VDU): 
  • Visual Display Unit is an Output Device that displays all work is done and images on its screen.
  • It is also called a Monitor. After processing the input, the result is shown on the Monitor.
  • The three most common specifications about the quality of monitors are Dot Pitch, Resolution, and Refresh Rate.
  • There are many types of monitor technologies are available like CRT (Cathode Ray Tube) monitors, LCD (Liquid Crystal Display) monitors, LED (Light Emitting Diode), OLED (Organic Light Emitting Diode), etc.

• Keyboard: The keyboard is one of the main Input Devices used in a computer. It is used to enter text and numeric data in a computer system. 
• Mouse: It is also called a Pointing Device which is used to point to the things on the monitor screen. It is an Input Device that was invented by Douglas Engelbert.
• Light Pen: A light pen is an Input Device, similar to a mouse. It is used to directly write and draw any figure on the computer screen.

Input Devices	Output Devices
Scanner	Printer
Microphone	Speaker
Joystick	Plotter
Web Camera	Screen Image Projector
Touch Screen	Monitor