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 Kirchhoff’s laws to potential dividers and sensing circuits.

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.