Break into small particles. The heat causes the rock to break up and form pebbles or sand. Hope that helped. Have a nice day
What happens is the potential value of the conductor decreases due to the presence of second conductor
as the capacitance is given by C = q/v
the value of v deceases as v-v1
thus the new capacitance is = C' = q/v-v1 thus the lowering of v increases the capacitance