Respuesta :
Answer
80 coils
Explanation
The turn rule of a transformer says that, the amount of voltage induced in the secondary coil is proportional to the number of coil. It is simplified by the ratio:
Np/Ns  =  Vp/Vs
200/Ns  = 25,000/10,000
200 × 10,000  = 25,000Ns
2,000,000 = 25000Ns
Dividing both sides by 25,000,
Ns = 2,000,000/25,000
    = 80 coils