When a heating coil is cut into two pieces and these two pieces are arranged in parallel and again worked in the same heater, the quantity of heat generated will increase compared to the original coil. This is because the total resistance of the parallel arrangement of the two pieces will be less than the resistance of the original coil.
According to Ohm's law, the amount of heat generated in a resistor is proportional to the square of the current passing through it and the resistance of the resistor. As the resistance of the parallel arrangement of the two pieces of the coil decreases, the current passing through the coil will increase for the same applied voltage. Therefore, the total amount of heat generated by the two pieces of the coil will be greater than the heat generated by the original coil.