Heating Effect of Electric Current

The heating effect of electric current and the applications of heating effect of electric current are both interconnected. You must have observed that the circuit fuse of the house breaks up during a sudden increase in the potential difference. Or the electric bulb becomes hot after a while of growing constantly. What are those? 

They are the applications of the heating effect of electric current in our day to day lives. The electric bulb would not glow if it was not provided with the required amount of electricity and the fuse wire would not have melted if it was not provided with enough heat. 

Heating effect of electric current 

The heating effect of electric current is explained as the amount of heat produced in a conductor when a flow of electric current is discharged through it. According to the laws of conservation of energy; Energy can neither be created nor be destroyed; it just can be changed from one form to another one i.e., energy is interchangeable. 

Also, the total energy in any system is always preserved i.e., it is constant and doesn’t increase or decrease in any circumstances. Electric current is partially used to perform work and the rest of it gets converted into heat energy. This process is known as the heating effect of electric current or the joule’s law of heating. 

The equation derived for the heating effect of electric current:

The work done to move a unit of charge from one place to another, w = Q×V (charge × potential difference) 

Amount of current in the conductor = Q/T (charge / time taken) 

Resistance of the conductor = V×I (potential difference × electric current) 

Hence, V = IR 

Now, putting Q = I ×T and V = IR, we get, 

       Work done (w) = I²RT 

The heat produced = I²RT 

Where, I stand for the amount of electric current flowing through the conductor. 

R stands for the resistance of the conductor 

T stands for the time for which the electric current flows through the conductor. 

This is known as joules law and it states that the amount of heat produced in a conductor is directly proportional to the: 

1. Square of the amount of electric current flowing through it. 
2. Resistance of the conductor through which the current flows. 
3. Time for which the electric current flows through the conductor. 

Another name for the heating effect of electric current is also the ohmic heating effect of the electric current. 

Applications of heating effect of electric current 

• Electrical heating appliances: The electrical appliances used for heating purposes in the household, for example, iron, toaster, geyser, electric kettle, microwave oven and room heaters work on the principle of heating effect of electric current. 
• Electric iron: The electric iron works on the principle of heating effect of electric current. In the electric irons, bimetallic plates are used to break the flow of current when the amount of heat reaches a specific amount. The broken circuit is represented by a red bulb glowing at the side of the body of iron. 
• Electric bulbs: Electric bulbs are another example that uses the heating effect of electric current as its principle application. When the current is made to pass through the circuit the filament of the bulb starts glowing which is of very high resistance. Once the flow of current starts the filament gradually becomes hot and starts to emit light which we use in our household. 
• Electric fuse: Another example of the heating effect of electric current is showcased by the electric fuse which we use in our household. The fuse is made up of a thin wire of low melting point as when an abrupt flow of current passes through the main circuit the wire in the fuse gets heated up and starts to melt and hence breaking the circuit. The electric fuse is used to prevent fire due to electrical appliances in our house. 

Conclusion 

By now we have already seen and understood the heating effect of electric current, its derivation and the applications of the heating effect of electric current. When we observe, the heat energy is just a normal part of our life, for our day to day activities but the scientific explanation unfolds many unexplored aspects of their properties.