Heating Effect of Current class-10 | cbse24

When an electric current is passed through a high resistance wire, like nichrome wire, the resistance wire become very hot and produced heat. This is called the heating effect of current. The heating effect of current is obtained by the transformation of electrical energy into heat energy

When Electric Charge Q moves against a potential difference V,the amount of work done is given by

W=Q x V....................................(1)

From the definition of current we know that

I=Q/t

so Q=I x t..................................(2)

And from Ohm's law we have V/I=R

or Potential difference V=I x R....................(3)

Value of equation (2 ) and (3) Put in equation (1)

we got W=It x IR

Assuming that all the electrical work done or all the electrical energy consumed is converted into heat energy, we can write 'Heat produced' in place of work done in the above equation .This formula gives us the heat produced in joules when a current of I amperes flows in a wire of resistance R ohms for time t seconds. This is known as joule's law of heating.

According to joule's law of heating the heat produced in a wire is directly proportional to

1:Square of current

2:Resistance of wire R

3:Time t ,for which current is passed

Application of heating effect of current:

1:The heating effect of current is utilized in the working of electrical heating application such as electric iron, electric kettle, electric toaster, electric oven ,room heater, water heater etc.

2:The heating effect of electric current is utilized in electric bulb for producing light

3:The heating effect of electric current is utilized in electric fuse for protecting household wiring and electrical appliances.

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