Video tapes and tapes used in the material and the role of the principle is basically the same, but the sound recording audio signal representative of the sound, and video recording is representative of the scene of the TV signal. In television signals, there are not only sound signals but also image signals. Video Tapes Tape recording tapes have a higher recording density than audio tapes because the recorded tape recording wavelength is on the order of microns for sufficient sensitivity and signal-to-noise ratio in this wavelength range. The magnetic grain size must be small and the surface of the magnetic layer must smooth. Moreover, the surface of the magnetic layer must have good abrasion resistance so that it can be used under high-speed friction with the magnetic head and in the fixed part of the tape transport system. For this reason, the adhesive used must be heat-resistant and wear-resistant.

Used in computer magnetic storage devices and magnetic cards used as magnetic cards for passenger vouchers and fare settlement, and the principle of action used by magnetic tapes used in magnetic tapes and the principle of operation are basically the same, but with different uses. There is a narrow tape on the magnetic card. When you take the subway from station A to station B, you put a ticket (coin) from station A to station B at station A and then put a magnetic card In the process of throwing this magnetic card has been recorded to get off at the B station magnetic records, take this magnetic card ride to B station into the instrument, the door open, outbound. If you did not get off at station B, but get off at station B, which is far away from station B, the coins you put in are not enough and you will not get out of the station. To take a magnetic card after the ticket to the station.

The process of putting a magnetic card in station B or station C is a process in which the magnetic recording is converted into an electrical signal by a magnetic head. Then use the signal control station door switch.

Magnetic materials used in the motor core generally hard ferrite, these materials are characterized by easy demagnetization after magnetization. Resistance to magnetic flux is small.