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...
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...
