(A) State two applications of Joule's heating in domestic electric circuit.

OR

(B) (a) Establish the relationship between the commercial unit of electric energy and the SI unit of electric energy.

(b) Determine the total resistance of the parallel combination of three resistances of $2 \Omega$, $4 \Omega$ and $6 \Omega$.

Two applications of Joule's heating in domestic electric circuit are:

(a) Electric bulb: The filament of an electric bulb is made of tungsten. When electric current flows through it, the filament gets heated up and produces light.

(b) Electric heater: Electric heaters like electric iron, electric toaster, etc. work on the principle of Joule's heating.