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 [...]
For burning a lamp, for running a fan or for giving supply to the armature of a d.c. motor, two wires are necessary. Through one wire the current enters into the machine or apparatus. This wire is called positive (+) wire. Through the other wire the current returns back to the supply source. This wire is called negative (-) wire. [...]
The following points highlight the three different metals used as fuse wire. The metals are: 1. Silver as Fuse-Wire 2. Copper as Fuse-Wire 3. Lead-Tin Alloy as Fuse-Wire. Metal # 1. Silver as Fuse-Wire: For fuse wires silver is quite satisfactory material. It is not subjected to oxidization as its oxide is unstable. The metal does not deteriorate when used [...]
In this article we will discuss about:- 1. Types of Switches 2. The Essential Qualities of a Switch 3. Positions. Types of Switches: i. Quick Break Knife Switch: This type of switch is generally used on the main switch board of a low voltage circuit. Fig. 76 shows a double pole quick break knife switch. The switch consists of one, [...]