Question 9 - Past Year - 1 Mark Questions - Chapter 12 Class 10 - Electricity

Write the mathematical expression for Joule’s law of heating.

Answer:

Joule’s law of heating states that the heat produced in a conductor is directly proportional to 

(i) the square of  the current I through it, 

(ii) its resistance R and 

(iii) the time t , for which current is passed.

Therefor, the mathematical expression of Joule’s law of heating is: 

     H = I ² Rt  

Where, 

• H = Produced Heat  
• I = Current flowing through the device  
• t = Time of current flow  
• R = Resistance of the appliance