Core Practical 2: Investigating Resistivity Aims of the Experiment The aim of the experiment is to determine the resistivity of a length of wire Variables Independent variable = Length, L, of the w...
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十月，是招生的黄金季，相信在接下来的一两个月内，2023择校大戏将进入高潮期，提前了解考试流程及内容，才能更加从容地面对春招大战。 而最新消息显示，光华剑桥2023年春季班招生考试将于2022年10月30日周日上午...
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...
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 ...
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...
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 ...
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...
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...
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...
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...
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:...
