The following points highlight the two main types of arrangement of resistance for conductors. The arrangements are: 1. Resistances in Series 2. Resistances in Parallel. Type # 1. Resistances in Series: When two or more conductors or coils or electrical appliances or resistors are joined together one after another to form a single circuit, they are said to be in [...]
An insulator is a substance possessing such enormous resistance that practically it does not permit electricity to flow through it. Electrons can be removed from the atom of any insulator with great difficulty. The outer electrons can be detached from their parent atoms when, in comparison with a conductor, considerably high amount of voltage is applied. Amongst the good insulators [...]
Every material offers a certain amount of opposition to the flow of electricity through it. Resistance may be defined in a general way as that property of a body which opposes the flow of electricity. A conductor is a substance of such small resistance that it readily allows electricity to flow through it. The best conductors Eire carbon and metals, [...]
In this article we will discuss how to determine effective value of alternating current and EMF, explained with the help of a suitable graph. In a graph plot the instantaneous values of current along the ordinate and the corresponding angular displacements along the abscissa for one complete cycle or 360°. A Sine curve will be obtained as shown in figure [...]
The following devices take leading current from the supply line: 1. Static Capacitor or Condenser 2. Over-Excited Synchronous Motor 3. Phase Advancer. Device # 1. Static Capacitor or Condenser: Static capacitor takes a current which leads the applied voltage by about 90°. Thus, it acts in direct opposition to inductance, neutralizes the inductive influence of the circuit and improves the [...]
The below mentioned article provides a formula for calculating power factor in the A.C. circuit. The power in watt absorbed by a d.c. circuit is known when the supply pressure in volt across the circuit is multiplied by the current in ampere flowing through the circuit. But in an a.c. circuit the product of supply pressure and the circuit current [...]
In this article we will discuss about:- 1. Classification of Wires 2. Types of Wires 3. Grade 4. Size. Classification of Wires: Wires may be classified into two groups: (i) Ordinary wires and (ii) Cables. For different electric work conductors used are usually made of copper, although aluminium conductors are also used extensively now-a-days. In India availability of copper is [...]
In this article we will discuss about the procedure for installation of metal-sheathed wiring. At first wooden plugs or rawl plugs or phil plugs are grouted in the wall at intervals not exceeding 75 cm (2 ½’). On to each plug suitably wide, polished, hard wood battens of thickness at least 10 mm (⅜") are screwed. The lead-covered cable is [...]
Conduit Wiring is the best system of wiring. There are two methods for laying conduits. In one method conduit is laid on the surface of the wall, ceiling etc. This is called surface wiring. The other method is to lay the conduit recessed in wall or ceiling, and this system is known as concealed wiring. Conduit may be rigid or [...]
Casing wiring is generally adopted for low pressure installations. Here V.I.R. wires or P.V.C. wires are laid in grooves. The two main disadvantages of this system of wiring are: (i) Very good workmanship is required to make the job perfect, and this results in costlier installation. (ii) There is every risk of fire from wood. Casing generally used for installation [...]