Electrical4U 
Two electric charges exert an attractive or repulsive force on each other. Like charges repel and opposite charges attract. For point charges at rest, Coulomb’s Law gives the force from the charge values, their separation and the surrounding medium. The familiar scalar-permittivity form assumes a uniform, linear and isotropic medium.Under those assumptions, three quantities set … Read more
Network Analysis determines voltages, currents and other responses in an electrical circuit model. A circuit element is connected to other elements in an electrical network, and an electrical circuit is analysed with its stated reference directions and operating conditions. Depending on topology, the circuit elements may be in series, in parallel or in a form … Read more
Different types of batteries use different electrode materials, electrolytes, cell formats and control systems. A battery supplies electrical energy through electrochemical reactions and may contain one cell or several connected cells. Primary batteries are designed for one discharge life. Secondary batteries are designed to be recharged under specified conditions. Neither class is always cheaper, safer, … Read more
A Daniell Cell is a zinc-copper galvanic cell developed as a more stable alternative to the early Voltaic Cell. It separates the zinc and copper reactions into different electrolytes, reducing the hydrogen polarisation that affected simple acid cells. A historical Daniell Cell produces about 1.1 V, although its voltage depends on solution activities and operating … Read more
A spirometer measures inspired or expired volume or flow as a function of time. Common spirometry results include forced vital capacity (FVC) and the volume expired in the first second (FEV₁). Simple spirometry does not measure residual volume or total lung capacity, because air remaining after complete expiration is not collected. Modern instruments are usually … Read more
A Half Adder is defined as a basic four terminal digital device which adds two binary input bits. It outputs the sum binary bit and a carry binary bit. A half adder accepts two binary inputs, A and B. Each input can be 0 or 1, so there are four input combinations: 0 + 0, … Read more
Power Line Carrier Communication (PLCC), more generally called power-line communication (PLC), superimposes communication signals on conductors that also carry electric power. Utility PLCC on high-voltage lines is distinct from low-voltage systems used for metering, automation or broadband networking. Reusing installed conductors can avoid a separate communication cable, but the power network is a difficult signal … Read more
A low-pressure sodium vapour lamp, also called an LPSV or SOX lamp, is a gas-discharge lamp. Its discharge operates in sodium vapour at low pressure and produces a narrow yellow-orange spectrum. The lamp was widely used for road, tunnel, industrial and security lighting where high lamp efficacy mattered more than accurate colour recognition. LED systems … Read more
White Light Emitting Diodes, or White LEDs, produce a spectrum that the eye perceives as white. They are used in indoor lighting, street lighting, flood lighting, displays, vehicles and indicators. Their efficiency, compact size and controllability have made them the main technology for many lighting applications. An individual LED normally emits light over a narrow … Read more
Ionization energy is the minimum energy required to remove an electron from an isolated neutral atom or molecule in its ground state. The first ionisation process forms a positive ion. Values may be given per particle in electron-volt eV or per mole in kJ/mol. Atomic ionisation energies are obtained from spectroscopic and collision measurements, then … Read more