8. Current Electricity
The chapter covers essential concepts of current electricity, including electric current, potential difference, and resistance. Key laws and formulas such as Ohm’s Law and Joule’s Law are discussed, along with the effects of electric current and the concepts of series and parallel resistor combinations. The chapter also introduces electric power, energy consumption, and circuit symbols used in electrical diagrams.
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Sections
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What we have learnt
- Electric current is the flow of electric charge and is measured in amperes.
- Potential difference, or voltage, is essential for current flow and is defined as work per unit charge.
- Ohm’s Law relates voltage, current, and resistance in a circuit.
Key Concepts
- -- Electric Current
- The flow of electric charge through a conductor, typically measured in amperes.
- -- Potential Difference
- The work done to move a unit charge between two points in an electric field, measured in volts.
- -- Resistance
- The opposition that a substance offers to the flow of electric current, measured in ohms.
- -- Ohm's Law
- The principle stating that the current through a conductor between two points is directly proportional to the voltage across the two points, represented as V = IR.
- -- Electromotive Force (EMF)
- The maximum potential difference between the terminals of a cell when no current is flowing, representing the energy supplied per coulomb of charge.
- -- Resistivity
- The measure of a material's ability to resist electric current, dependent on the material and temperature, and defined as R = ρl/A.
- -- Joule's Law of Heating
- The principle stating that the heat produced by an electric current is proportional to the square of the current, the resistance, and the time, given by H = I^2Rt.
- -- Electric Power
- The rate at which electric energy is consumed, measured in watts, and calculated using several formulas such as P = VI.
Additional Learning Materials
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