State Joule's law of heating. Express it mathematically when an appliance of resistance R is connected

State Joule's law of heating. Express it mathematically when an appliance of resistance R is connected to a source of voltage V and the current I flows through the appliance for a time t.

Answer 

This law states that heat produced in a resistor is:

• directly proportional to the square of current for a given resistance / (H α I²)
• directly proportional to the resistance for a given current / (H α R)
• directly proportional to the time for which the current flows through the resistor / (H α t)

H = V I t