Many people say that putting credit cards and mobile phones together will demagnetize them, but in fact they will not. Because most of today’s credit cards are chip cards, and even a bank card with a magnetic stripe will not be demagnetized if placed together with a mobile phone, because the energy form of the electromagnetic wave generated by the mobile phone is an electric field, not a magnetic field, and will not generate enough energy. The magnetic field force that changes the magnetic strip information on the bank card.