Potential Difference & Conductor Length Potential Difference A cell makes one end of the circuit positive and the other negative. This sets up a potential difference across the circuit The pote...
A-Level 商务（Business Management）和A-Level 经济（Economy）都是商科方向的课程。于是有很多学生会在选课阶段对着两门课程纠结不已，不知道究竟该选择哪门课程。事实上，虽然A-Level 商务（Business Manageme...
Calculating Current & Drift Velocity Drift Velocity In a conductor, the current is due to the movement of charge carriers The charge carriers can be negative or positive However current ...
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...
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...
