Cinematography works on the principle of

A tape recorder can be used both for recording and reproduction of sound with the help of

Magnetic recording and reproduction are made by

A radio set receives electro magnetic waves and converts them in to sound waves back with the help of

J.J. Thomson invented 

TV was invented by

The atomic number of an atom is equal to its

The wireless system was invented by

 TV  set receives waves through 

The particles emitted as a result of falling of light rays on certain metallic surfaces.