# On which of the following techniques photo state machine works ?

On which of the following techniques photo state machine works?

(1) Magnetic Image-Making

(2) Thermal Image-Making

(3) Electrostatic Image-Making

(4) Electromagnetic Image-Making

Answer: (3) All Electrostatic Copiers work under the premise that a charge of electricity is placed on an Image Drum which has the ability to retain the electric charge much like a capacitor holds its charge but with the ability to hold or release the charge depending on how much light and darkness is applied to the Image Drum. A photocopier (also known as a copier or copy machine) is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat. Copiers can also use other technologies such as inkjet, but xerography is standard for office copying.