When a current flows through a conductor, heat energy generates in the conductor.
The heating effects of electric current depend on three factors: First, the resistance of the conductor i.e. a higher resistance produces more heat, second the time for which the current flows i.e the longer the time, the amount of heat production is high and the third one is higher the current amount of heat generation is also large.
Hence the heating effect produced by an electric current, I through a conductor of resistance, R for a time, t is given by:
H =
This equation is Joule’s equation of electrical heating.
From the above equation, the heat energy is proportional to the square of the current produced in the conductor.
Hence if the current flowing through the heater coil is doubled, the heat produced will become four times. Hence option 2 is correct.