Joule law of heating is ___________.

Explanation

(i) 'I' be the current flowing through a resistor of resistance 'R' and 'V' be the potential difference across the resistor.
(ii) The charge flowing through the circuit for a time interval 't' is 'Q'.
(iii) The work done in moving the charge Q across the ends of the resistor with a potential difference V is VQ. This energy spent by the source gets dissipated in the resistor as heat. Thus, the heat produced in the resistor is :
H = W = VQ
(iv) You know that the relation between the charge and current is Q=It. Using this, we get
H =VI t -------------------(1)
From Ohm's law , V= IR. Hence, you hace
`H = I^(2) R t ` ----------------- (2)
This is known as Joule's law of heating.