Practical+electricity

=Electrical appliances=

When we are talking about practical electricity, we usually discuss about the electrical appliances that we use in our daily lives. Some of the types of these appliances include:

Electric thermal energy is used to boil water, iron clothes and cook food. This type of appliance uses the property of nichrome metal which heats up when current flows through it. Nichrome wires has a high resistivity and able to withstand high temperatures. In an electric kettle, the heating elemnt is enclosed in an insulated metal tube. Thermal energy is generated when an electric current through the heating element. In an electric iron, thermal energy generated by the heating element is spread evenly over a metal base which is a good conductor of heat.
 * I.** Electric heating

Although there are two types of elec﻿tric lamps, the filament lamp and the flourescent lamp, they both have electrical current flowing through them. In filament lamps, however, it uses a tungsten coil which has a high resistivity and melting point. The tungsten coil gets extremely hot and generates light when current flows through it. The glass bulb is usually filled with inert gases to prevent the tungsten from getting burnt at high temperatures. Meanwhile, in flourescent lamps, there are two electrodes and when electric charges pass between the two electrodes, the mercury vapour in the gllass tube emits ultraviolet light together by visible light.
 * II.** Electric lighting

=Electrical energy=

Energy is measured in Joules(J). For an appliance to work, it requires energy. Electrical energy is converted into other forms of energy such as heat, light and kinetic. The power(P) of an electrical appliance is defined as the amount of electrical energy that is converted into other forms of energy. The equation is given as:


 * P=E/t**

Whereby P is power, Q is the energy, and t is time.

Furthermore, if we can combine voltage with power, whereby voltage has the formula:


 * V=E/Q**

Whereby E is once again energy and Q is the charge,

We can also rewrite


 * P=E/t**

to


 * P=VI** or **P=RI^2** or **P=(V^2)/R**