Potential Dividers & Variable Resistance The Potentiometer A potentiometer is a single component which can act as a potential divider. It consists of a coil of wire with a sliding contact A var...
Potential Dividers The electrical voltages rule is defined as: The sum of the e.m.f.s in a closed circuit loop is equal to the sum of the potential differences around that loop Therefore, wh...
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...
