Primary coil, secondary coil, iron core, induced potential difference, magnetic field, alternating, current course overview. Physics and engineering of high power switching devices. Specified practical induced potential and transformers. Students solve practice problems on voltage, current, and impedance matching. Gcse physics revision science section on transformers and changing voltages of an ac supply. Ferrite, iron, operating frequency, core, size, power usage, mobile phone. Physics stack exchange is a question and answer site for active researchers, academics and students of physics. A transformer changes a highvoltage supply into a lowvoltage one, or vice versa. An isolation transformer does not change the voltage except for losses. Aqa p3 ppts for the transformers and transformers in action lessons of p3.
We have a brilliant team of more than 60 support team members looking after discussions on the student room, helping to make it a fun, safe and useful place to hang out. Since the input voltage is ac, a timevarying magnetic flux is sent to the secondary, inducing its ac output voltage. Gcse physics electromagnetism medium demand questions questionsheet 15 a the national grid is made up of a network of cables transmitting electricity from power stations across the country. This video covers transformer basics what they are made of and how they work. In a switch off position the current will not pass through the appliance and it will not work. Stepdown transformers are used in mains adapters and rechargers for mobile phones. One where the output voltage is larger than the input voltage. General certificate of secondary education foundation tier june 2015 physics ph3fp unit physics p3 wednesday 20 may 2015 1. Stepdown transformers decrease the voltage by having more turns onthe primary coil than on the secondary coil. This progress sheet is compiled from the edexcel physics gcse specification. It informs students what they are expected to know for this unit and allows them to assess their level of understanding of each requirement using a red, amber, green scale. A transformer that increases the voltage is called a stepup transformer. The transformer equation this equation is important the transformer equation relates the number of turns of wire to the difference in voltage between the primary and secondary coils v p vs np ns.
Learn about and revise transformer function and design, the transformer equation, and power calculations in transformers with gcse bitesize physics. How transformers change potential difference, stepup and stepdown transformers, how to use the transformer equation, benefits of switch mode transformers, examples and step by step solutions, gcse igcse physics, notes. Transformers change the voltage of an alternating current ac electrical supply. Magnetic field lines are not real, but are a useful model to help us to understand. Further topics at the end can be selected to provide the right mix of pages for the syllabus. This gcse physics electricity quiz will see how much you know about transformers. The switch mode transformer how it works gcse physics. The main advantages of using switch mode transformers over other types of transformers are that they have a greater efficiency, they are smaller in size and lighter in weight. Transformer is a static device which simply stepsup or stepsdown the voltage,or current without changing the supply frequency.
A transformer has a primary coil of 100 turns and a secondary coil of 300 turns. In a step up transformer there are more coils of wire on the secondary coil than on the primary coil. Gcse physics science revision section covering circuits, current, voltage, resistance, amps, volts, ohms, ohms law, electrons. Isaac physics a project designed to offer support and activities in physics problem solving to teachers and students from gcse level through to university. Electricity a units b mains electricity c energy and potential difference in circuits d electric charge a units students will be assessed. In a switch on position the current passes through the appliance and it starts functioning. Unofficial aqa physics unit 3 gcse new spec mark scheme official aqa gcse physics 23rd may 20 mark scheme physics. One where the output voltage is the same as the input voltage. Now i need to order the design for transformer and the transformer design centre asking for dot polaritystartend point of pins.
Which coil has more turns in a step down transformer. There will always be at least small losses of power usually as heat in a transformer that prevent them from being 100% efficient. Time allowed 1 hour instructions use black ink or black ballpoint pen. Electricity notes gcse physics this means that if you want a current to flow you must put a battery in the circuit. Gcse physics the transformer equation voltage number. A transformer that decreases the voltage is called a stepdown transformer. Static and current electricity scool, the revision website. Edexcel as physics revision guide by tim tuggey, 9781846905957, available at book depository with free delivery worldwide. A typical power station generates electricity at 25000 v. My revision notes biology, chemistry, physics and combined science. Aqa gcse physics third edition book where to get answers.
This tutorial explains how switch mode transformers work and compares them to traditional iron core transformers. Static and current electricity topic for gcse physics including revision notes, revision guides and question banks. Fundamental physicselectricitytransformer wikiversity. Design and use of transformers transformers higher aqa. Electricity is usually transported on the national grid at around 450,000 volts. Switch mode transformers high frequency, mobile phone chargers. Induced potential, transformers and the national grid. Transformers are simple devices that convert voltage from high to low and.
Universal physics higher tier instructions use black ink or ballpoint pen. Have a free meeting with one of our hand picked tutors from the uks top universities. General certificate of secondary education gcse and a. The size of the electric current is the rate of flow of electrical charge. When dc current of 50hz passes through the primary coil of transformer it will be generating some magnetic filed around primary coil. Np is the number of turns of wire on the primary coil. It can increase the voltage called a step up transformer, shown below or decrease the voltage called a step down transformer how does a step up transformer work alternating current is passed through the primary coil the input which creates a changing magnetic field in. Design and use of transformers higher transformers edexcel. Switch mode transformers switch mode transformers vs. Physics ph3fp unit physics p3 thursday 23 may 20 9. Ferrite, iron, operating frequency, core, size, power usage, mobile phone chargers. Since the voltage is increased then this means the current is reduced.
Transformers use electromagnetic induction to change the voltage of alternating currents. It also covers the two equations you need to learn for your exams with an exa. New gcse aqa physics transformers lesson teaching resources. This time we connect a cell with an output of 4 volts. This resource is a whole lesson with resources for the transformers section of the new aqa physics specification. Gcse electricity revise how transformers convert voltage. What is a transformer a transformer is made from two coils, one on each side of a soft iron core. Find out how by playing this quiz written by teachers to help year 10 and year 11 pupils revise. Learn about and revise induced potential and its applications in generators, loudspeakers and transformers with gcse bitesize physics. Edexcel gcse physics, electromagnetic induction progress. Static and current electricity scool, the revision website jump to navigation. Confused about polarity of transformer stack exchange. In a transformer power in power out so, you might also like.
A transformer is an electrical device that changes the voltage of an ac supply. Complete physics covers all syllabuses due to a unique combination of core pages and further topics. Tutorials, tips and advice on gcse physics coursework and exams for students, parents and teachers. Electricity and circuits edexcel gcse physics separate.
Separate science, topic 10 electricity and circuits, gcse science, separate science, dexcel, gcse science, xam board, edexcel, physics, exam board, ks4. Delivery guide for ocr gcse 91 physics a gateway science. Mains electricity is ac alternating current the electricity in the mains supply switches direction 50 times per second. For examiners use question mark gcse and alevel revision. What is an advantage of using switch mode transformers over a traditional. A transformer has 200 turns on its primary coil, and 50 on its secondary coil.
Some lighting circuits have dimmer switches that allow you to control the brightness of the bulbs. This can be used by students, teachers and parents to direct revision at weaker areas prior to tests and exams. Current electricity is a flow of charged particles. Stepup transformer, stepdown transformer pass my exams. Each chapter contains core material valid for all syllabuses. These devices convert voltage from high to low or viceversa which makes transporting and using it so much easier. Physics transformers examples, solutions, videos, notes. A switch is a device used for operating electrical appliance.
Which one of the following is the correct reason for this a the internal resistance of the battery will not allow enough current in the primary coil. The ammeter reads 2 amps and the lamp glows brilliantly. Ac alternating currentpotential what does a transformer do. Switch mode transformers operate at high frequency, between 50 khz and 200 khz.
A transformer is a device that changes transforms and alternating potential difference voltage from one value to another value be it smaller or greater using the principle of electromagnetic induction. Stephen pople, one of todays most respected science authors, has created a totally new physics book to prepare students for examinations. Transformers are used, as an example, because the generation of electricity is at very high voltage and consumption is at very low voltages, so in order to maintain these requirements we use. The aqa gcse science textbooks are in the aqa approval process. For a straight transformer with an ac voltage applied to the primary and a secondary on load, the ampere turns of the secondary magneto motice force is totally cancelled by the ampere turns in the primary that resulted from that secondary load. A transformer cannot be used to run a 230 v, 100 w mains lamp directly from a 12 v car battery. Fill in the boxes at the top of this page with your name, centre number and candidate number. Stepdown transformers are used in mains adapters and rechargers for mobile phones and cd players. Trilogy specification reference gcse combined science. A transformer is used to stepup the electricity leaving the power station to a very high voltage. One to one online tution can be a great way to brush up on your. Transformer power transfer transformers edexcel gcse. The voltage and current changes can be calculated, as the power transfer is constant.
But this is too fast to see so lights dont appear to flicker although they are, 50 times every second. Physics and engineering of high power switching devices monographs in modern electrical technology. Edexcel gcse centre number candidate number surname other names write your name here physicsscience unit p1. A simplest switch consists of two contacts, one is fixed and the other is movable. Gcse physics what are advantages of a switch mode transformer. This video contains some general information about transformers, but goes on to look more specifically at the advantages of switch mode transformers, as covered by the aqa exam board. As part of their work on electricity, gcse physics students will look at transformers. Current, voltage, resistance gcserevision, physics. Content additional notes from dr c electric current is a flow of electrical charge. Ferrite, iron, operating frequency, core, size, power usage, mobile phone chargers course overview menu skip to content. Some times transformers make the output voltage bigger than the input voltage, this is a step up transformer.