A 1000 V/400 V power transformer has a nominal short-circuit voltage Vsc = 40%. Which one of the following statements is correct ?
(a) A voltage of 400 V appears across the short-circuited secondary terminals.
(b) A voltage of 16 V appears across the short-circuited secondary terminals.
(c) When the secondary terminals are short-circuited, the rated current flows at the primary side at a primary voltage of 400 V.
(d) The primary voltage drops to 400 V, when the secondary terminals are short-circuited.