Answer
(a) Less than 1000W
(b) II
Work Step by Step
(a) We know that $P=\frac{V^2}{R}$. This equation shows that power consumed is inversely proportional to the resistance. Since the heaters are connected in series while the voltage remains constant, the resistance is doubled and as a result the power consumed is decreased to less than 1000W.
(b) The best explanation is option (II) -- that is, the voltage is the same, but the resistance is doubled by connecting the heaters in series. Therefore, the power consumed $(P=\frac{V^2}{R})$ is less than 1000W.
