In a parallel circuit, each additional branch increases the size of the main line current that must be drawn from the battery. One of the most important applications of a pn junction diode is the rectification of alternating current ac into direct current dc. Kirchoffs first law the sum of the currents flowing into a junction of wires must equal the sum of the currents flowing away from the junction of wires. Dc electricity answers alevel physics curriculum press. In an electric circuit there should be a device that acts like the water pump in a fountain source of emf. Then we will step through each of these topics in detail. The equivalent capacitance of the three capacitors is. Dc is generally provided by batteries or via a transformer, rather than generators. Module 1 covers the basics for circuits that include dc sources voltage or current. Thus, the equivalent resistance of the combination must get smaller. I 0 2nd law around any closed loop in a circuit, the algebraic sum of the individual p.
It can be used in potential divider circuits to monitor and control temperatures. In the figure on the right, the thermistor has a resistance of 800. Relationship between voltage current and resistance. Jan 19, 2020 january 19, 2020 november 17, 2010 by mini physics this topic covers dc circuits of a level physics. A level physics electricity complete circuits questions aqa, edexcel author. The key to solving this problem is to recognize the structure of the circuit. Current originates in the movement of charged particles usually electrons around a circuit. The sum of the currents entering a junction is equal to the sum of the currents leaving that junction. Random errors are errors of measurements in which the measured quantities differ from the mean value with different magnitudes and directions. In a large number of electronic circuits, we require dc voltage for operation.
Students must apply kvl to determine the voltage drop across r1, and then use ohms law to calculate its current. Potential difference voltageemf in a battery, a series of chemical reactions occur in which electrons are transferred from one terminal to another. This is a good example of how kirchhoffs voltage law is more than just an abstract tool for mathematical analysis it is also a powerful technique for practical circuit diagnosis. Click to read even more a level physics notes and download our comprehensive revision material today. As physics revision notes unit 2 electricity and thermal physics electricity 1. A level physics definations the following are all the definitions youll need when studying for your physics alevel exam. Reduce the original circuit to a single equivalent resistor, re. The think sheets are synchronized to readings from the physics classroom tutorial and to missions of the minds on physics program. General electronic circuits operate on low voltage dc battery supplies of between 1. Alevel physics dc direct current circuits 5 powerpoints.
Calculating resistance, voltage, and current using ohms law. Summary notes, key points, flashcards, videos and past exam questions by topic for edexcel physics as and alevel topic 3 electric circuits. January 19, 2020 november 17, 2010 by mini physics this topic covers dc circuits of a level physics. Circuits make computers, digital cameras, and video games possible. The greater the cells current the more work is done against the cells internal resistance, and therefore less can. Volume 2 of 4 module 3 dc circuits this module introduces the rules associated with the reactive components of inductance and capacitance and how they affect dc circuits. A cell in a circuit has its own internal resistance, r. Electromotive force and circuits no steady motion of charge in incomplete circuit. Reduce the original circuit to a single equivalent resistor, redrawing the circuit in each step of reduction as simple series and simple parallel parts are reduced to single, equivalent resistors. Jan 19, 2020 january 19, 2020 may 14, 2012 by mini physics this topic covers dc circuits of o level physics. A level physics electricity complete circuits questions ocr author.
Workshop tutorials for biological and environmental physics er2b. In a series circuit, regardless of where it is measured, current will always give the same value. In this topic youll learn about the physics behind the electronic devices we use. As, a level, physics, worksheets, revision, resources, complete circuits, ocr created date. Using the equation for electrical power, we can rearrange to solve for. Jul 31, 2017 a direct current dc circuit usually has a steady and constant voltage supplied to it. It is the conversion of chemical energy into electrical energy. Energy transferred through a power supply per unit coulomb in a circuit. A level students revision for chemistry, physics, geography and maths.
Dc circuits open textbook library center for open education. If you plug something in the wall it runs on ac although some devices internally convert the ac alternating current into dc. Learners are encouraged to open the simulator and explore. Using this relationship, 2 show that p i2r b the p. Electrical symbols electrical circuits, ac and dc gcse. In this article, the fundamentals of electric charge, current, potential difference, resistance and conservation of charge are discussed. As, a level, physics, worksheets, revision, resources, complete circuits, aqa, edexcel created date. Seriesparallel dc circuits worksheet dc electric circuits. Dc current and ac current have different effects on the human body, both are dangerous above a certain voltage level.
Module 2 basic dc theory this module describes the basic concepts of direct current dc electrical circuits and discusses the associated terminology. The values of each resistor can therefore be found using. The differences between series and parallel circuits should be explored practically and learners should develop a clear understanding of the nature of current flow in these circuits. Three ammeters, placed at various points in an exclusively series circuit will give identical readings. In this device, the charge travels uphill from lower to higher v opposite to. Rules of series and parallel circuits are very important for students to comprehend. Students understanding of direct current resistive electrical circuits.
There is a potential difference voltage between these poles. The voltage source, the capacitor, and the two resistors are in parallel. A level physics electricity complete circuits questions aqa. Equivalent to advanced placement if this is too advanced for you, you can try the more basic version here. Students will work hard to memorize the rules without really comprehending why the rules are true, and therefore often fail to recall or apply the rules properly.
The transition from ks4 to ks5 is never entirely easy, and physics throws up its own. Compare and contrast series, parallel and combination circuits. Electrical circuits are connected in series or in parallel. Instructor what we will introduce ourselves to in this video is the notion of electric circuits and ohms law, which you can view as the most fundamental law or the most basic law or simplest law when we are dealing with. These are the answers to the circuits practice questions for gcse physics. Being an html5 simulation, it is compatible with tablets such as the ipad, with chromebooks, and with all mobile devices. Dc circuits are simply those in which the current moves in one direction only thus direct current dc. Current in series and parallel circuits conservation of charge the total charge flowing into a junction of wires must equal the total charge flowing out of the junction. Three capacitors, of capacitance 1f, 5f, and 6f, are arranged in a circuit with a switch and a 12v battery as shown above. Current can be measured at any point in a series circuit and give the same result at a junction in a circuit, current splits in proportion to the resistance in each branche. The circuit symbol for an alternating voltage source is a circle with a sine wave. In the diagram on the right, the current splits into proportions dependent on the resistors.
Current can be measured at any point in a series circuit and give the same result at a junction in a circuit, current splits in proportion to the resistance in each branch. Determine the potential at w when the temperature is hot. In this device, the charge travels uphill from lower to higher v opposite to normal conductor due to the emf force. These are the answers to the dc electricity practice questions for a level physics. Electric circuits the following pdf files represent a collection of classroomready think sheets pertaining to the topic of motion in one dimension. This book covers direct current dc circuit theory and is broken up into three modules. Related questions and their answers of ac current and dc current. Students understanding of direct current resistive electrical circuits by. The voltage source, the capacitor, and the two resistors are in parallel to each other, meaning that they have the same voltage. Its resistance decreases with increasing temperature. However, more in struments need to be developed in a variety of areas to allow instructors to better evaluate their students understanding of physics concepts. We can easily convert the ac voltage or ac current into dc voltage or dc current by using a device called pn junction diode. Basic electrical quantities formulas with simple explanation in dc circuits.
In a parallel circuit it is the voltage which remains constant through each arm of the circuit. Learning outcome 3 focuses on differences between ac and dc. Introduction to electronics ii dedication human beings are a delightful and complex amalgam of the spiritual, the emotional, the intellectual, and the physical. In parallel circuits, this equivalent resistance is always smaller than any of the original resistors. Introduction to circuits and ohms law video khan academy. There are two types of current, alternating current ac and direct current dc. Teachers may print the entire packet or individual think sheets. This textbook on physics is designed to contain everything you need to know for the ocr physics b advancing physics specification. A level physics electricity complete circuits questions ocr. Correctly construct circuits from circuit diagrams using d. C dc current and ac current have different effects on the human body, both are dangerous above a certain voltage level. Capacitance, resistance, dc circuits 20, richard white. A direct current does not have a continually changing polarity, unlike an alternating current ac, but instead a constant direction and rate of flow.
Circuits and motion and forces, can be reassuring to year 12 students they. We can easily convert the ac voltage or ac current into dc voltage or dc current by using a device called pn junction diode one of the most important applications of a pn junction diode is the rectification of alternating current ac into direct current dc. Circuits are driving an unprecedented rate of change in how we live. Do all this without the fear of being electrocuted as long as you dont use your computing device in the bath tub. Systematic errors are errors of measurements in which the measured quantities are displaced from. These are the answers to the dc electricity practice questions for alevel physics. Equivalent to american high school diploma if this is too basic for you, you can try the more advanced version here. Dc circuit builder can be used to easily explore simple circuits, series circuits, parallel circuits, combination circuits, and more. Optics and wave phenomena such as wave properties, superposition, interference, diffraction, geometrical optics. Directcurrent circuits chapter 21 electric current and. Distribute cells or dc powerpacks, resistors, wires, voltmeters and ammeters.
1422 594 240 1439 715 1115 119 254 1479 305 776 236 788 133 47 1416 619 1262 1327 1221 620 558 829 911 332 768 822 1084 611 1444 31 1351 1245 335 1167 825 1092 1434 642 363 804 1190 934 1461 1148 1267 767 3 1299