Electrical4U 
The electron configuration of an atom states how its electrons are distributed among atomic orbitals, usually for the ground state. It helps explain periodic trends, bonding with other atoms, conductivity and magnetic field response. A configuration is a model description with defined quantum numbers, not a map of electrons travelling on fixed paths. What is … Read more
Steam flashing occurs when hot pressurised water or condensate passes to a pressure below the saturation pressure for its temperature. Part of the liquid becomes vapour without added heat. The result depends on the inlet enthalpy and final pressure. It differs from normal steam generation in a boiler, where a heat source raises water enthalpy. … Read more
Thermal conductivity k relates conductive heat flux to a temperature gradient through Fourier’s law. Its SI unit is watt per metre-kelvin, written W/(m·K). The conductivity of metals varies with composition, purity, microstructure and temperature, so a useful value must identify the material condition and test temperature. What is a Metal? A metal is a material … Read more
A diode is a two-terminal semiconductor device with a strongly directional relationship between electric current and voltage. Its terminals are the anode and cathode; these names do not mean fixed positive and negative terminals in every circuit state. A diode is forward-biased when its anode is at a higher voltage than its cathode. It normally … Read more
Magnetostriction is the strain produced in some magnetic materials when their magnetization changes. A specimen may lengthen, shorten or change volume in an applied magnetic field. The size and sign of the response depend on the material, crystallographic direction, initial magnetic state, stress, temperature and the magnitude and direction of the magnetic field. The direct … Read more
A surface steam condenser removes heat from turbine exhaust steam and returns it to liquid form. Condensing at a low pressure reduces turbine backpressure and allows the turbine to extract more energy. Because the steam and cooling water remain separated by tube walls, suitable condensate can return to the steam cycle. In a typical water-cooled … Read more
A transformer transfers AC electrical energy between coupled windings by electromagnetic induction. In power systems, transformers change voltages, provide galvanic isolation when designed for it and connect systems with specified winding arrangements. Three-phase units are also identified by their vector group. A transformer vector diagram, more precisely called a phasor diagram, shows the steady-state magnitude … Read more
A deaerating heater, also known as a deaerator, is defined as a device that removes dissolved gases, mainly oxygen and carbon dioxide, from boiler feedwater. These gases can cause corrosion and damage to the boiler and its parts, reducing steam cycle efficiency. Therefore, deaerating heaters are crucial for boiler water treatment and protection. Deaerating heaters … Read more
A wet natural draft cooling tower is a direct-contact heat and mass exchanger. It rejects heat from circulating water to the atmosphere, mainly by evaporating a small part of the water into the air. Power stations and large process plants use these towers when the project scale justifies the tall structure. No fan drives the … Read more
A thermopile is an array of thermocouples that produces an electrical voltage when its measuring and reference junctions are at different temperatures. It uses the thermoelectric effect, but a uniform temperature alone produces no net output. A thermopile contains several thermocouples, each made from two dissimilar conductors. A temperature difference between its junctions produces a … Read more