A transformer has 400 turns on its primary coil and 200 turns on its secondary coil. The secondary coil supplies current Is to a resistive load. If the number of turns on the secondary is suddenly increased to 400 while the primary voltage remains the same, what happens to Is (assume the transformer is ideal)?
a) Is doubles
b) Is becomes half of its previous value
c) Is remains unchanged
d) Is becomes four times its previous value