OCR AS level Physics: Resistance

OCR AS level Physics: Energy, Power, and Resistance

OCR AS level Physics presentations for module 4: Energy, Power, and Resistance. All presentations come with worked examples, solutions and homeworks. This covers topics from circuit symbols to paying for electricity. * All circuit symbols required for OCR A level physics * Polarity of cells and batteries * Electron flow and conventional current * Calculating the base SI units for volts * Comparing potential difference and electromotive force (emf). * Circuit diagrams for measuring potential difference and emf. * Calculating energy dissipated in a circuit. * The structure of an electron gun. * The electron gun in the history of science (J.J. Thomson). * Rearranging equations to equate kinetic energy and work done. * Accelerating potential differences * Comparing the protons and electrons accelerated in a potential difference * Definition of an ohm. * Temperature and resistance for metallic conductors (wires) * The ohm in base SI units * I against V graphs and resistance * I-V Characteristics curves for ohmic components * I-V Characteristics curves for non-ohmic components * Circuit diagrams used to measure I and V. * Describing I-V Characteristics curves * Polarity of diodes * Conventional current and diodes * Plotting I-V curves for diodes * Describing I-V curves for diodes * Factors affecting resistance * Calculating resistivity * Resistivity and temperature * Experimentally determining resistivity * Using a graph to calculate resistivity * Thermistor uses * Thermistors with negative temperature coefficients * Plotting I-V curves for thermistors * Creating an experiment to test thermistors. * Materials and uses of LDRs * Creating an experiment to understand LDRs * LDRs relationship with light intensity * Converting time to hours * Using different units for electrical energy * Converting from J to kW hr * Calculating the cost of using different electrical appliances.