Electrical

Alternative energy refers to energy sources which could replace coal, traditional gas and oil, all of which increase the atmospheric carbon when burned as fuel. Renewable energy implies that it is derived from a source which is automatically replenished or one that is effectively infinite so that it is not depleted as it is used.

The electromotive force (e.m.f.), E, of a cell is the p.d. between its terminals when it is not connected to a load (i.e. the cell is on ‘no load’). The e.m.f. of a cell is measured by using a high resistance voltmeter connected in parallel with the cell. The voltmeter must have a high resistance

A material must contain charged particles to be able to conduct electric current. In solids, the current is carried by electrons. Copper, lead, aluminium, iron and carbon are some examples of solid conductors. In liquids and gases, the current is carried by the part of a molecule which has acquired an electric charge, called ions.

(a) Colour code for fixed resistors The colour code for fixed resistors is given in table. Colour Significant Figures Multiplier Tolerance Silver – 10-2 ±10% Gold – 10-1 ±5% Black 0 1 – Brown 1 10 ±1% Red 2 102 ±2% Orange 3 103 – Yellow 4 104 – Green 5 105 ±0.5% Blue 6

The movement of electric charge drives the current in a circuit. The negatively charged atom-containing particles known as electrons are responsible for carrying electric charge. A power source, like a battery or generator, in a circuit produces an electric potential difference between two points. The electrons move from the power source’s negative terminal through the

All atoms consist of protons, neutrons and electrons. The protons, which have positive electrical charges, and the neutrons, which have no electrical charge, are contained within the nucleus. Removed from the nucleus are minute negatively charged particles called electrons. Atoms of different materials differ from one another by having different numbers of protons, neutrons and

Symbols are used for components in electrical circuit diagrams and some of the more common ones are shown in Fig. Read More Topics Electrical / electronic system block diagram Electrical potential and e.m.f Types of solar collectors for heat Hydro electric power plant classification

An electrical / electronic system is a group of components connected together to perform a desired function. Figure shows a simple public address system, where a microphone is used to collect acoustic energy in the form of sound pressure waves and converts this to electrical energy in the form of small voltages and currents; the

When a direct current of I amperes is flowing in an electric circuit and the voltage across the circuit is V volts, then power, in watts P =VI Electrical energy = Power × time = VIt joules Although the unit of energy is the joule, when dealing with large amounts of energy, the unit used

The unit of electric resistance is the ohm(Ω), where one ohm is one volt per ampere. It is defined as the resistance between two points in a conductor when a constant electric potential of one volt applied at the two points produces a current flow of one ampere in the conductor. Thus, [latex] \begin{aligned} \text