The Correct Answer is Electromagnetic induction. Swiping a credit card is based on the principle of Electromagnetic inductionElectromagnetic or magnetic induction is the production of an electromotive force across an electrical conductor in a changing magnetic fieldExample: When we swipe the card, the credit card machine's coil of wires causes a change in the magnetic field. This is called electromagnetic induction. The change in magnetic field induces a voltage that creates a current that is used to signal your account information to the machine. When we swipe a magnetic-strip card, the technology transmits the bank information to the card reader, which sends it to Square. Then it is passed along that information to the acquiring bank. Square's magstripe reader plugs into your iOS or Android device's headset jack so we can take credit card payments anywhere. Additional InformationFrictional force refers to the force generated by two surfaces that contacts and slide against each other. Rubbing both hands together to create heat is an example of frictional force. Photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. Applications of the photoelectric effect brought us "electric eye" door openers, light meters used in photography, solar panels and photostatic copying.