Ohm's Law Ohm’s law states: For a conductor at a constant temperature, the current through it is proportional to the potential difference across it Constant temperature implies constant resi...
Electric Current & Potential Difference Electric Current Electric current is defined as the rate of flow of positive charge carriers It is measured in units of amperes (A) or amps ...
Required Practical: The Young Modulus Aims of the Experiment The aim of the experiment is to measure the Young Modulus of a metal in the form of a wire This requires a clamped horizontal wir...
The Young Modulus The Young modulus is the measure of the ability of a material to withstand changes in length with an added load This gives information about the stiffness of a material Thi...
Conservation of Energy in Deformation Loading and Unloading a Metal Wire When a metal wire is loaded with a force and stretched beyond its limit of proportionality, it will undergo plastic d...
Plastic Behaviour Materials can undergo two types of deformations: Elastic deformation When the load is removed, the object will return to its original shape This is shown in the elastic reg...
Elastic Strain Energy Work has to be done to stretch a material Before a material reaches its elastic limit (whilst it obeys Hooke's Law), all the work is done is stored as elastic strain energy Th...
Tensile Stress & Strain Opposite forces can deform an object If the forces stretch the object, then they are tensile forces Tensile forces lead to the two properties of materials known a...
Hooke's Law When a force F is added to the bottom of a vertical metal wire of length L, the wire stretches A material obeys Hooke’s Law if: The extension of the material is directly proporti...
