Details Title: AQA P3 Module Transformers Description: AQA Physics Module 3 revision cards for transformers Total Flash Cards: 10 Created: 05/02/2008 04:09:54		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Physics Flashcards
Cards in this set: Term Why is mains electricty AC? Definition Generators produce AC and transformers need AC to work. Term Describe a transformer Definition A transformer is two coils of wire both wrapped around a circular core made of a magnetic material like iron.  One coil is connected to an AC power source. Term Describe a step up transformer Definition A step up transformer has less turns on the primary coil than the secondary coil. It makes potential differences bigger and currents smaller. Term Describe a step down transformer Definition A step down transformer has more turns on the primary coil than the secondary coil. It makes potential differences smaller and currents bigger. Term What does the primary coil behave like? Definition The primary coil has an alternating current flowing through it so it is an electromagnet but because the current changes so does the strength of the electromagnet.  So it produces a changing magnetic field (behaves like a moving magnet) Term Why is a potential difference created in the secondary coil? Definition THe secondary coil cuts through the cahnging magnetic field line produced by the primary coil hence a potential difference is generated Term Describe an electromagnet Definition An electromagnet is a coil (solenoid) of wire carrying an electric current. It has the same shape magnetic field as a bar magnet. Term How can you make an electromagnet stronger? Definition You can make the electric current larger. You can increase the number of turns on the coil. You can put a magnetic material like iron or steel inside the coil. Term How would an electromagnet behave if an alternating current (AC) flows through it? Definition The strength of the electromagent would get stronger (as the current got bigger) and weaker (as the current got smaller). The magnet would switch poles (when the current changed direction). The electromagnet would behave like a moving magnet. Term What happens to a current carrying wire when placed in a magnetic field? Definition The moving electrons in the wire will feel a force and this makes the wire move.