Bipolar junction transistors generally comprise n-p-n or p-n-p junctions of either silicon (Si) or germanium (Ge) material. The junctions are, in fact, produced in a single slice of silicon by diffusing impurities through a...
Tag - Electrical engineering
Arsenic, antimony and phosphorus have five valency electrons and when a semiconductor is doped with one of these substances, some impurity atoms are incorporated in the tetrahedral structure. The ‘fifth’ valency electron is...
When a conductor is moved across a magnetic field so as to cut through the lines of force (or flux), an electro motive force (e.m.f) is produced in the conductor. If the conductor forms part of a closed circuit then the e.m.f...
If a current-carrying conductor is placed in a magnetic field produced by permanent magnets, then the fields due to the current-carrying conductor and the permanent magnets interact and cause a force to be exerted on the...
The solenoid is very important in electromagnetic theory since the magnetic field inside the solenoid is practically uniform for a particular current, and is also versatile, inasmuch that a variation of the current can alter the...
Magnetic fields can be set up not only by permanent magnets, but also by electric currents. Let a piece of wire be arranged to pass vertically through a horizontal sheet of cardboard on which is placed some iron filings, as shown...
(a) Capacitors connected in parallel Figure shows three capacitors, C1, C2 and C3, connected in parallel with a supply voltage V applied across the arrangement. When the charging current I reaches point A it divides, some...
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...
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...
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...