Heating effect of electric current uses - SSLC Physics chapter one

Heating effect of electricity have many uses. It is widely used in several appliances.  When current passes through a conductor material, it is getting heated and this heat is being used according to consumer requirements. Some of the devices using heating effect are listed below.

• Electric Iron
• soldering Iron
• Electric heater
  

In each of the appliances there is a common coil which is getting heated. This coil should have some properties

that is  

• High resistivity - it is a property of material( ). If resistivity incrases resistance also increases. So we can say that high resistance is required for heating coils.
• Ability to remain in red hot condition for along time without getting oxidised(Oxidation means the formation of metal ions due to some reaction happening on its surface)

generally heating coils are made of NICHROME. It is an alloy of Nickel, Chromium and Iron. Properties of Nichrome make it useful for using as heating coil in heating appliances.

Those properties are

• High Resistivity
• High Melting point ( Melting point - The temperature at which the material start melting)
• Ability to remain in red hot condition for  long time without getting oxidised.

Another use of heating effect of electric current is in safety fuses.

Safety fuse

In electrical circuit, if high current passes through the circuit , the appliances connected in the circuit may get damaged . In our house hold connections due to lightning or by other factors , high current may come to our connections, it causes damages to the appliances. To protect the devices from such high currents (or overloads) , we use safety fuse. The name itself suggest that , it is used for safety purposes.

The fuse is made of alloy of Tin and Lead.

Working: When high current passes through fuse wire ,it gets heated up . And it will start melting and suddenly connection get interrupted due to broken fuse wire.

Therefore fuse wire should be connected series in the circuit . So that its braking causes interruption in the current flow to the appliances.

from observing the working of safety fuse, we can easily write its properties.

Those are

• Comparatively low reisistivity.
• Low melting point.