Multiple choice

Which of the following devices consists of a photoelectric cell, which is packed into a slender tube having the dimension of a pen?

  1. Touch screen

  2. Light pen

  3. Scanner

  4. OMR

  5. Joystick

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This device consists of a photoelectric cell which is packed into a slender tube having the dimension of a pen.