Edexcel A Level Physics:复习笔记3.9 Electrical Resistivity
Electrical Resistivity All materials have some resistance to the flow of charge As free electrons move through a metal wire, they collide with ions which get in their way As a result, they t...
Edexcel A Level Physics:复习笔记3.8 Current-Potential Difference Graphs
Current-Potential Difference Graphs As the potential difference (voltage) across a component is increased, the current also increases (by Ohm’s law) The precise relationship between voltage ...
Edexcel A Level Physics:复习笔记3.7 Electrical Power
Electrical Power Work is also defined as a transfer of energy When components transfer electrical energy to other stores, work must be done because energy is transferred Therefore, potential differ...
Edexcel A Level Physics:复习笔记3.6 Resistance in Series & Parallel
Deriving Equations for Resistance in Series & Parallel Resistors In Series When two or more components are connected in series: The combined resistance of the components is equal to the sum of ...
Edexcel A Level Physics:复习笔记3.5 Energy Conservation in Circuits
Energy Conservation in Circuits The Electrical Voltages Rule (Kirchhoff's Second Law) Energy is never used up or lost in a circuit, since everything follows the Law of Conservation of Energy The el...
Edexcel A Level Physics:复习笔记3.4 Charge Conservation in Circuits
Charge Conservation in Circuits The Electric Current Rule (Kirchhoff's First Law) The electric current rule is defined as: The algebraic sum of the currents entering and leaving a junction is equal...
Edexcel A Level Physics:复习笔记3.3 Ohm's Law
Defining Resistance Resistance Resistance is defined as the opposition to current It is further defined by Ohm's Law, which says that the resistance of a conductor is given by the ratio of p...
Edexcel A Level Physics:复习笔记3.2 Potential Difference
Potential Difference Potential Difference A cell makes one end of the circuit positive and the other negative This sets up a potential difference across the circuit This is sometimes known as the v...
Edexcel A Level Physics:复习笔记3.1 Electric Current
Electric Current Electric Current Electric current is defined as: The rate of flow of charge It is measured in units of amperes (A) or amps The charge, current and time are related by the equation:...
