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<?xml version="1.0" encoding="UTF-8"?> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops"> <head><title>08 ElectricCircuits</title></head> <body><h1>Electric Circuits</h1> <h2>Section title</h2> <div class="teachers-guide" data-unknown="true"><div class="title"></div> <p>Notes</p> <p>The following topics are covered in this chapter.</p> <ul data-class="ListBulleted"><li> Ohm's Law <ul data-class="ListBulleted"><li>Define potential difference as the work done per unit positive charge <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>V</mi> <mo>=</mo> <mfrac> <mi>W</mi> <mi>q</mi> </mfrac> </mrow><annotation encoding="math/tex">V=\frac{W}{q}</annotation></semantics></math></li> <li>Define current as the rate of flow of charge <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>I</mi> <mo>=</mo> <mi>q</mi> <mi>t</mi> </mrow><annotation encoding="math/tex">I=qt</annotation></semantics></math></li> <li>Determine the relationship between current and potential difference at constant temperature </li> <li>State Ohm's Law: Current through a conductor is directly proportional to the potential difference across the conductor at constant temperature </li> <li>Distinguish between Ohmic and non-Ohmic conductors </li> <li>Define resistance as a material's opposition to the flow of electric current </li> <li>State that the unit of resistance is the ohm </li> <li>Calculate the effective resistance of resistors in series using <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <msub> <mi>R</mi> <mi>T</mi> </msub> <mo>=</mo> <msub> <mi>R</mi> <mn>1</mn> </msub> <mo>+</mo> <msub> <mi>R</mi> <mn>2</mn> </msub> </mrow><annotation encoding="math/tex">R_T=R_1+R_2</annotation></semantics></math></li> <li>Calculate the effective resistance of resistors in parallel using </li> <li>Interpret circuit diagrams containing a source, switches, resistors, ammeters and voltmeters </li> <li>Solve problems using the mathematical expression of Ohm's Law <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>R</mi> <mo>=</mo> <mfrac> <mi>V</mi> <mi>I</mi> </mfrac> </mrow><annotation encoding="math/tex">R=\frac{V}{I}</annotation></semantics></math>  for series and parallel circuits, limited to a maximum of three external resistors </li> </ul></li> <li> 2. Power and Energy <ul data-class="ListBulleted"><li>Solve problems using electrical energy <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>W</mi> <mo>=</mo> <mi>P</mi> <mi>t</mi> </mrow><annotation encoding="math/tex">W=Pt</annotation></semantics></math></li> <li>State that electrical energy is measured in joules (J) </li> <li>Know that electrical power dissipated in a device is equal to the product of the potential difference across the device and current flowing through it </li> <li>Solve problems using <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>P</mi> <mo>=</mo> <mi>V</mi> <mi>I</mi> </mrow><annotation encoding="math/tex">P=VI</annotation></semantics></math> or <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>P</mi> <mo>=</mo> <msup> <mi>I</mi> <mn>2</mn> </msup> <mi>R</mi> </mrow><annotation encoding="math/tex">P=I^2R</annotation></semantics></math> or <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>p</mi> <mo>=</mo> <mfrac> <msup> <mi>V</mi> <mn>2</mn> </msup> <mi>R</mi> </mfrac> </mrow><annotation encoding="math/tex">p=\frac{V^2}{R}</annotation></semantics></math></li> <li>Solve problems using <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>W</mi> <mo>=</mo> <mi>V</mi> <mi>I</mi> <mi>t</mi> </mrow><annotation encoding="math/tex">W=VIt</annotation></semantics></math> or <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>W</mi> <mo>=</mo> <msup> <mi>I</mi> <mn>2</mn> </msup> <mi>R</mi> <mi>t</mi> </mrow><annotation encoding="math/tex">W=I^2Rt</annotation></semantics></math> or <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>W</mi> <mo>=</mo> <mfrac> <msup> <mi>V</mi> <mn>2</mn> </msup> <mi>R</mi> </mfrac> <mi>t</mi> </mrow><annotation encoding="math/tex">W=\frac{V^2}{R}t</annotation></semantics></math></li> <li>Know that the kilowatt hour (kWh) is a unit of energy and that 1 kWh is the amount of energy used when 1 kilowatt of electricity is used for 1 hour </li> <li>Calculate the cost of electricity usage given the power specifications of the appliances used as well as the duration if the cost of 1 kWh is given </li> </ul></li> <li> 3. Internal Resistance and Series and Parallel Networks <ul data-class="ListBulleted"><li>Solve problems involving current, voltage and resistance for circuits containing arrangements of resistors in series and in parallel for a maximum of three external resistors </li> <li>State that a real battery has internal resistance </li> <li>Define emf as the total energy supplied per coulomb of charge by the cell </li> <li>The sum of the voltages across the external circuit plus the voltage across the internal resistance is equal to the emf: <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>e</mi> <mi>m</mi> <mi>f</mi> <mo>=</mo> <msub> <mi>V</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>l</mi> <mi>o</mi> <mi>a</mi> <mi>d</mi> </mrow> </msub> <mo>+</mo> <msub> <mi>V</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>i</mi> <mi>n</mi> <mi>t</mi> <mi>e</mi> <mi>r</mi> <mi>n</mi> <mi>a</mi> <mi>l</mi> <mi>r</mi> <mi>e</mi> <mi>s</mi> <mi>i</mi> <mi>s</mi> <mi>t</mi> <mi>a</mi> <mi>n</mi> <mi>c</mi> <mi>e</mi> </mrow> </msub> </mrow><annotation encoding="math/tex">emf=V_{load}+V_{internal resistance}</annotation></semantics></math> or <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow> <mi>e</mi> <mi>m</mi> <mi>f</mi> <mo>=</mo> <mi>I</mi> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>e</mi> <mi>x</mi> <mi>t</mi> </mrow> </msub> <mo>+</mo> <mi>I</mi> <mi>r</mi> </mrow><annotation encoding="math/tex">emf=IR_{ext}+Ir</annotation></semantics></math></li> <li>Solve circuit problems in which the internal resistance of the battery must be considered </li> <li>Solve circuit problems, with internal resistance, involving seriesparallel networks of resistors to a maximum of three external resistors</li> </ul></li> </ul><figcaption></figcaption></div></body> </html>