An input device that uses switch contacts placed under a plastic pad which may be inscribed with symbols is known as

Punched card
Touch pad
Magnetic disk E. None of the above

The correct answer is B. Touch pad.

A touch pad is an input device that uses a conductive surface to detect the movement of a user’s finger. It is typically used to control the cursor on a computer screen, but can also be used to select items or enter text.

A punched card is a piece of stiff paper that has been punched with holes to represent data. Punched cards were used as a data storage and input medium for computers and other machines from the 1920s to the 1980s.

Punched paper tape is a long, narrow strip of paper that has been punched with holes to represent data. Punched paper tape was used as a data storage and input medium for computers and other machines from the 1950s to the 1980s.

A magnetic disk is a data storage device that uses a magnetic field to store data. Magnetic disks are typically used in hard drives, floppy disks, and other storage devices.

E is not the correct answer because it is not an input device.