ALTERNATING CURRENT AND DIRECT CURRENT

            TOPIC: ALTERNATING CURRENT AND DIRECT CURRENT

Class - 7

OBJECTIVE  :

Students should able to know the difference between AC and DC

Description of Topic:

Introduction of Alternating current & Direct Current, Sources of AC & DC, Uses of AC & DCs, Static and dynamic electricity

Introduction : 

 We use electricity for many purposes. Using electrical energy several items (appliances) like lights, tubes fans, torch light will work. Most of the appliances are labeled with a name plate or product label on which operating electrical supply - AC or DC is to be used for functioning of the appliance.

Alternating current (AC) and Direct Current (DC) Supply :

Most of the domestic lighting and heating system make use of alternating current. We have some appliances which work on Direct Current. Before connecting the device we should ensure operating supply - whether the appliance works on AC or DC. Sometimes an appliance may work both on AC and DC. In an AC supply the terminals are identified as phase and neutral. The phase wire can be identified by placing a neon tester on it. The supply voltage of AC is 230 Volts in our houses.

In DC, supply terminals are identified as positive and negative. The appliance working on DC is also marked for its polarity. The positive form the supply must be connected to positive terminal of the appliance. If we interchange the connection, it may damage and appliance.

Sources of AC & DC: 

The AC supply is usually given by electrical board and DC source is available in batteries and cells.

Uses:

AC is useful to run many electrical appliances like lights, tubes etc.DC is useful in torch lights, Emergency lights, Satellites etc.Type your paragraph here.