Answer:
20:1
Step-by-step explanation:
It is given that,
Input voltage = 260 volt
Output voltage = 13 volt
We need to find the ratio of the number of input wire coils to output wire coils on the transformer.
For a step-down transformer,
[tex]\dfrac{V_i}{V_o}=\dfrac{N_P}{N_S}\\\\\dfrac{N_P}{N_S}=\dfrac{260}{13}\\\\=\dfrac{20}{1}[/tex]
Hence, the required ratio is 20:1.